In-situ TEM investigation of the effect of nano twins on the evolution of He bubbles under thermo-mechanical coupling conditions

In this study, the in-situ TEM tensile experiment was performed on the Nb-modified GH3535 alloy after He ion irradiation at 750 °C, to investigate the influence of the nano twins on the evolution of irradiation-induced He bubbles under thermo-mechanical coupling conditions. The results suggest that the interaction between the He bubbles and nano twins may contribute to the abnormal irradiation hardening observed in Nb-GH3535 alloy, in addition to the effects of the He bubbles and precipitate strengthening. Moreover, the merger and coarsening of the He bubbles under the influence of the nano twins provide direct experimental evidence supporting the previously proposed stress-assisted coarsening mechanism for the He bubbles. [Display omitted]