Revealing the impact of chemical short-range order on radiation damage in MoNbTaVW high-entropy alloys using a machine-learning potential

TL;DR

This study demonstrates that chemical short-range order enhances radiation tolerance in MoNbTaVW high-entropy alloys by promoting defect recombination, but its rapid degradation under irradiation limits long-term benefits.

Contribution

It reveals how CSRO influences radiation damage processes and assesses its stability, providing insights for designing more radiation-resistant high-entropy alloys.

Findings

CSRO promotes interstitial diffusion and defect recombination.

CSRO enhances radiation tolerance but degrades rapidly under irradiation.

Loss of CSRO reduces long-term radiation resistance.

Abstract

The effect of chemical short-range order (CSRO) on primary radiation damage in MoNbTaVW high-entropy alloys is investigated using hybrid Monte Carlo/molecular dynamics simulations with a machine-learned potential. We show that CSRO enhances radiation tolerance by promoting interstitial diffusion while suppressing vacancy migration, thereby increasing defect recombination efficiency during recovery stage. However, CSRO is rapidly degraded under cumulative irradiation, with Warren-Cowley parameters dropping below 0.3 at a dose of only 0.03~dpa. This loss of ordering reduces the long-term enhancement of CSRO on radiation resistance. Our results highlight that while CSRO can effectively improve the radiation tolerance of MoNbTaVW, its stability under irradiation is critical to realizing and sustaining this benefit.