Influence of Al Content on Oxidation Resistance of Phase-pure Ti2AlC under Simulated Loss-of-coolant Accident Conditions

To tailor Ti 2 AlC coatings for the applications in accident tolerant fuels, the oxidation of near-stoichiometric and Al-lean Ti 2 AlC was investigated in Ar-41% H 2 O atmosphere in 1000-1200 ℃.The oxidation kinetics of phase-pure Ti 2 AlC in high-temperature water vapor varied from parabolic to linear rate law with Al content decreasing.Insufficient Al content could not sustain the growth of continuous alumina scales, resulting in formation of thick unprotective TiO 2 -based scales.The formation of thin and protective Al 2 O 3 scale for Ti 2 AlC with stoichiometric composition effectively inhibited the inward diffusion of water vapor.For the application of protective coatings on Zr-based cladding, stoichiometric Ti 2 AlC is expected to protect cladding from fast oxidation and improve the accident tolerance in the current light water reactors.