Suppression of helium clustering in tungsten via dilute vanadium alloying
Year: 2026
Type: article
Abstract: Helium clustering in W-based plasma-facing materials in fusion reactors critically influences bubble nucleation and irradiation resistance. Using molecular dynamics simulations, we investigate He clustering behaviour in W-V and W-Ta alloys across a temperature range of 300 to 1500 K. While oversized Ta solutes in W-Ta induce increased He clustering at high temperatures, dilute W-V alloys ( < 20 at.% V) exhibit an anomalous inverse relationship whereby the He clustering fraction decreases with increasing temperature. We attribute this to the weak self-trapping due to lattice mismatch and concentration effects. In dilute W-V alloys, the undersized V atoms create local tensile strain that provide energetically favourable lattice locations for He accommodation and weakens the driving force for He self-trapping. Consequently, although He atoms aggregate at room temperature, the clusters are thermally unstable and dissociate at elevated temperatures rather than stabilizing via vacancy formation.
Source: Scripta Materialia
Institution: University of Helsinki
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,220
OpenAlex ID: W7154693183