Abstract: Tungsten/graphene/tungsten and tungsten/graphane/tungsten nanolayered composites were developed and applied as the plasma facing materials of nuclear fusion devices. The formation energies of the helium interstitial atom and tungsten vacancy and the mechanical properties of the two nanolayered composites were investigated by first-principles calculation. The results indicate that the tungsten/graphene/tungsten and tungsten/graphane/tungsten nanolayered composites exhibit resistance to radiation dam-age to some extent. The tungsten/graphene and tungsten/graphane interfaces serve as sinks for both the helium interstitial atom and tungsten vacancy and as sites for the self-healing performance of tungsten self-interstitial and vacancy. The results based on the Fukui function reveal that these features of the tungsten/graphene and tungsten/graphane interfaces are associated with the change in the activity of tungsten atoms. An interesting finding of this study is that the ductility of tungsten-based materials can be enhanced and the anisotropy factor reduced by inserting monolayer graphene into the tungsten crystal.

Key words: tungsten, graphene, graphane, plasma facing materials, ?rst principles, Fukui function