Mechanisms of Microstructural Evolution and Degradation in Aluminum under High-Damage Irradiation
Abstract
Aluminum alloys are widely used in research reactor systems, yet the mechanisms governing irradiation-induced degradation remain poorly understood. Here we combine conventional cascade-overlap molecular dynamics simulations with an accelerated Iterative Kinetic Approach (IKA) to investigate defect evolution in single-crystal Al subjected to 50 keV He irradiation. Benchmarking shows that IKA reproduces the essential defect kinetics of cascade simulations while enabling access to substantially higher accumulated damage. By extending the IKA to higher damage levels, we identified three distinct regimes governing radiation-induced degradation in Al: recombination-driven annihilation, defect accumulation, and sink-controlled absorption. At higher damage, Frank loops dissociate into Shockley partials and stair-rod loops, ultimately driving the nucleation and growth of stacking-fault tetrahedra (SFTs). These transformations progressively convert mobile defects into SFTs. Ultimately, the synergistic effect of interstitial and vacancy loops and SFTs increases irradiation hardening in Al at 300 K. This work provides insight into irradiation-induced degradation in aluminum reactor materials.
Versions
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BibTeX
@misc{issaka2026mechanisms,
title = {{Mechanisms of Microstructural Evolution and Degradation in Aluminum under High-Damage Irradiation}},
author = {Alhassan S. Issaka and Sadie Wicks and Vishal Yadav and Assel Aitkaliyeva and Michael R. Tonks and Simon R. Phillpot},
howpublished = {arXiv},
year = {2026},
month = jul,
doi = {10.48550/arxiv.2607.22364},
eprint = {2607.22364},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.22364},
}
RIS
TY - UNPB
TI - Mechanisms of Microstructural Evolution and Degradation in Aluminum under High-Damage Irradiation
AU - Alhassan S. Issaka
AU - Sadie Wicks
AU - Vishal Yadav
AU - Assel Aitkaliyeva
AU - Michael R. Tonks
AU - Simon R. Phillpot
PY - 2026
DA - 2026/07/24
PB - arXiv
DO - 10.48550/arxiv.2607.22364
UR - https://arxiv.org/abs/2607.22364
AB - Aluminum alloys are widely used in research reactor systems, yet the mechanisms governing irradiation-induced degradation remain poorly understood. Here we combine conventional cascade-overlap molecular dynamics simulations with an accelerated Iterative Kinetic Approach (IKA) to investigate defect evolution in single-crystal Al subjected to 50 keV He irradiation. Benchmarking shows that IKA reproduces the essential defect kinetics of cascade simulations while enabling access to substantially higher accumulated damage. By extending the IKA to higher damage levels, we identified three distinct regimes governing radiation-induced degradation in Al: recombination-driven annihilation, defect accumulation, and sink-controlled absorption. At higher damage, Frank loops dissociate into Shockley partials and stair-rod loops, ultimately driving the nucleation and growth of stacking-fault tetrahedra (SFTs). These transformations progressively convert mobile defects into SFTs. Ultimately, the synergistic effect of interstitial and vacancy loops and SFTs increases irradiation hardening in Al at 300 K. This work provides insight into irradiation-induced degradation in aluminum reactor materials.
ER -