UKAEA-CCFE-PR(25)327

Thermodynamic Assessment of the Quaternary WTaCrV Refractory High Entropy Alloy as a Means to Guide Experimental Approaches

High-entropy alloys (HEAs) are being explored as potential candidates for radiation-tolerant materials, with some compositions exhibiting good resistance to defect cluster formation. One such system is WTaCrV, although only a single composition has been experimentally tested under ion irradiation, where it showed phase decomposition at low temperature. In this work, we systematically investigate the thermodynamic properties of the entire quaternary composition space. Using a combination of first-principles calculations, cluster expansion, and Monte Carlo simulations, we access temperature-dependent free energy functionals, short-range ordering parameters, and atomic configurations that can be compared with experimental observations. These data are then used to construct the phase stability map and thermodynamic databases (TDBs) that illustrate BCC phase stability across the composition space. Our results identify compositional regions that are less likely to undergo phase separation at low temperatures. These insights provide predictive guidance for selecting compositions that are more likely to remain single-phase solid solutions, which we have validated with experimental results.

Collection:
Journals
Journal:
Acta Materialia
Publisher:
Elsevier