2019 journal article

Insights into the plastic behavior of irradiated Ni-based alloy through in-situ TEM experiments: Formation and evolution of defect-free channels

JOURNAL OF NUCLEAR MATERIALS, 523, 33–42.

By: D. Kaoumi n  & V. Jammot

co-author countries: United States of America πŸ‡ΊπŸ‡Έ
author keywords: In-situ TEM; Dislocation dynamics; Radiation damage; Ni-based alloy; Inconel 617; Ion irradiation; Plasticity
Source: Web Of Science
Added: July 29, 2019

Foils of Ni-based alloys are deformed in situ in a TEM at 298 K after irradiation at the same temperature to 1014 ions/cm2 with 1 MeV Kr ions. The irradiation effects on the dislocation sources, dislocation motion, and on dislocation interactions with each other and the microstructure are assessed through in-situ dynamic observations. Dislocation motion through the irradiated material is observed to be jerky and discontinuous, as they get pinned by the irradiation-induced defects and the progression of the pile-ups proceeds in bursts of multiple dislocations. Active sources of dislocations originating from the walls of the channels are captured in-situ. They provide dislocations that glide in the channel and progressively clear it of the defects. Dislocation interactions with irradiation defects result in their increase in length by absorption of the defects; dislocations can become longer than the width of the channel, which can lead to congested channels and heavily jogged dislocations, resulting in a higher driving force for dislocation cross-slip out of the channels into the outside matrix, a phenomenon also captured in-situ. Similar observations were done in both Inconel 617 and Haynes 230, a similar Ni-based alloy with different composition but similar Stacking Fault Energy, indicating that the mechanisms at play are not strongly dependent on the chemical composition.