An investigation into the potential importance of helium trapping during the nucleation of radiation-induced voids

Transmission electron microscopy has been used to investigate the effect of small modifications in the concentration of #betta#'-forming elements (Al, Ti and Si), in a model nickel-based superalloy, upon the formation of helium bubbles during post-implantation annealing. The results show that bubble formation and growth can be significantly influenced, and in some cases inhibited, depending upon specific combinations of elements that partition to #betta#'. The results are discussed in relation to the possible mechanisms involved and their potential importance in minimizing void swelling in nuclear reactor constructional materials. (orig.)