Traditional alloys typically consist of one principal element with small amounts of other elements added to improve properties. High-entropy alloys (HEAs) break this mold, containing multiple principal elements in near-equal atomic proportions, resulting in a unique "high-entropy effect." This effect gives HEAs many excellent properties, making them promising for applications in aerospace, energy, and other fields. Previous research suggested that plastic deformation in HEAs is primarily caused by dislocation motion. Elastic deformation refers to a material's ability to return to its original shape after the removal of an external force. Typically, elastic deformation does not cause permanent changes in the material. However, this study reveals that HEAs can undergo a transformation from a crystalline to an amorphous state under elastic deformation!
Methods
Highlights✨
Discovery of a new amorphization mechanism: This study changes the conventional belief that only plastic deformation can lead to amorphization, revealing a novel deformation mechanism in HEAs. Clarification of the role of local atomic environment heterogeneity: The research elucidates how the unique local atomic environment heterogeneity in HEAs suppresses dislocation nucleation, promoting elastic strain-induced amorphization. Integration of advanced research techniques: The study combines in situ mechanical testing, HRTEM, atomic-resolution chemical mapping, and first-principles calculations to reveal the mechanism of elastic strain-induced amorphization from both experimental and theoretical perspectives.
Reveals a new deformation mechanism in HEAs: Provides new insights into the mechanical behavior of HEAs, contributing significantly to the fundamental research in materials science.
Guides new material design: By controlling the elastic strain-induced amorphization behavior in HEAs, it is possible to design HEAs with superior mechanical properties.
Fig. 2. The local inhomogeneity in HEAs
Fig. 3. Atomic-scale element distribution analysis for ternary TiZrNb alloys.
The co-first authors of this work are Prof. Ye-Qiang Bu from Zhejiang University and Prof. Yuan Wu from the University of Science and Technology Beijing. Prof. Yuan Wu from the University of Science and Technology Beijing, Prof. Jia-Bin Liu from Zhejiang University, Prof. Hong-Tao Wang from Zhejiang University, and Prof. Zhao-Ping Lü from the University of Science and Technology Beijing are the corresponding authors of this paper.
Y. Bu, Y. Wu, Z. Lei, X. Yuan, L. Liu, P. Wang, X. Liu, H. Wu, J. Liu, H. Wang, R.O. Ritchie, Z. Lu, W. Yang, Elastic strain-induced amorphization in high-entropy alloys, Nature Communications 15(1) (2024) 4599. https://doi.org/10.1038/s41467-024-48619-0
