Theory-guided design of high-entropy alloys with enhanced strength-ductility synergy

• Published in: Nature communications Vol. 14; no. 1; p. 2519
• Main Authors: Pei, Zongrui, Zhao, Shiteng, Detrois, Martin, Jablonski, Paul D, Hawk, Jeffrey A, Alman, David E, Asta, Mark, Minor, Andrew M, Gao, Michael C
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 02.05.2023; Nature Publishing Group UK; Nature Portfolio
• Subjects: Alloys; Design; Design parameters; Ductility; Entropy; Face centered cubic lattice; High entropy alloys; Mechanical properties; Metastable phases
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-38111-6

Metallic alloys have played essential roles in human civilization due to their balanced strength and ductility. Metastable phases and twins have been introduced to overcome the strength-ductility tradeoff in face-centered cubic (FCC) high-entropy alloys (HEAs). However, there is still a lack of quantifiable mechanisms to predict good combinations of the two mechanical properties. Here we propose a possible mechanism based on the parameter κ, the ratio of short-ranged interactions between closed-pack planes. It promotes the formation of various nanoscale stacking sequences and enhances the work-hardening ability of the alloys. Guided by the theory, we successfully designed HEAs with enhanced strength and ductility compared with other extensively studied CoCrNi-based systems. Our results not only offer a physical picture of the strengthening effects but can also be used as a practical design principle to enhance the strength-ductility synergy in HEAs.