Synergism of Al and Si occurs on corrosion of Ti3Al1−xSixC2 MAX in the static Pb-Bi eutectic at 550 ºC.

MAX phase ceramics attract increased attention for lead-cooled fast reactors due to their promising compatibility with lead-bismuth eutectic (LBE). This work systematically investigates the corrosion behaviors of five Ti 3 Al 1−x Si x C 2 MAXs with Al/Si complex A component in static LBE at 550 ºC up to 3000 h. Based on the lattice structure, mechanical properties, surface morphologies, and elemental composition during corrosion, a synergism of Al and Si during oxidation and diffusion is found, which contributes to a continuous and well-attached Al 2 O 3 layer with improved LBE corrosion resistance. Therefore, the multi-element design will bring a broad space for the applications of MAX ceramics. • Ti3Al1−xSixC2 presents an enhanced corrosion resistance in Pb-Bi eutectic. • The continuous Al2O3 layer is proven as the crucial anti-corrosion species. • Moderate amount of Si is beneficial for a thin and continuous Al2O3 layer. [ABSTRACT FROM AUTHOR]