Enhancing intrinsic ductility in VNbMoTaW high entropy alloy: A combinatorial investigation with experimental evaluation of theoretical predictions

Authors

• Taohid Bin Nur Tuhser, University of KentuckyFollow
• Ian Stewart Winter, University of California - Berkeley
• Daryl Chrzan, University of California - Berkeley
• Thomas John Balk, University of KentuckyFollow

Abstract

The application of refractory high entropy alloys (RHEAs) as engineering materials has been hindered by their poor inherent ductility. In this study, a novel approach combining thin film combinatorial screening with fragmentation testing was employed to identify intrinsically ductile alloy compositions. Inspired by the physics-based intrinsic ductility parameter, the ‘χ-parameter,’ we investigated the replacement of group VI elements (W/Mo) with group V elements (V, Nb, Ta) in the VNbMoTaW system. Conventional combinatorial analyses, including composition, phase, and hardness assessments, were conducted across a wide range of non-equiatomic configurations. The results revealed a broad compositional space favoring a single-phase body-centered cubic (BCC) solid solution with comparable hardness, despite significant differences in element concentrations. Thin film fragmentation testing was then performed on VNbMoTaW, VNb₂TaW, VNbMoTa₂, V₂NbTaW, and V₂NbMoTa systems, establishing a ductility trend based on crack onset strain (COS) and residual stress. To further validate the thin film findings, indentation fractography was performed on bulk samples. The replacement of Mo with Nb emerged as the most effective strategy for enhancing ductility in both experiments. Finally, experimental results were compared against five theoretical approaches.

Document Type

Article

Publication Date

2025

Notes/Citation Information

2238-7854/© 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Digital Object Identifier (DOI)

https://doi.org/10.1016/j.jmrt.2025.02.011

Funding Information

This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Award # DE-SC0019402. Sandia National Laboratories is a multimission laboratory managed and operated by the National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA-0003525. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy (DOE) or the U.S. Government.

Repository Citation

Tuhser, Taohid Bin Nur; Winter, Ian Stewart; Chrzan, Daryl; and Balk, Thomas John, "Enhancing intrinsic ductility in VNbMoTaW high entropy alloy: A combinatorial investigation with experimental evaluation of theoretical predictions" (2025). Chemical and Materials Engineering Faculty Publications. 123.
https://uknowledge.uky.edu/cme_facpub/123