A novel way to enhance hydrogenation resistance of nano-layered titanium silicon carbide by the doping of aluminium

Abstract The outstanding irradiation and corrosion resistance of nano-layered Ti 3 SiC 2 make it suitable for cladding materials in advanced nuclear systems. However, Ti 3 SiC 2 shows the relatively poor thermal stability in hydrogen circumstance at high temperature, which is a big obstacle for its nuclear related applications. In this paper, we proposed an effective approach to improve the hydrogenation resistance of Ti 3 SiC 2 by the doping of Al. The experimental results demonstrated that compared to pure Ti 3 SiC 2 , Ti 3 Si 0.9 Al 0.1 C 2 (TSAC) displayed much better hydrogenation resistance. Through first-principles calculation, it was concluded that the introduction of H interstitial atom made the formation energy of Al vacancy much lower, so Al atoms became much easier to remove from TSAC than Si atoms and Ti atoms. The preferable loss of aluminium from TSAC substrate gave rise to the formation of Al 2 O 3 layer, which improved the hydrogenation resistance of TSAC by inhibiting further reaction between TSAC and hydrogen.