Recently, the research team from Beijing Institute of Technology (BIT)'s School of Materials Science and Engineering, led by Professor Cheng Xingwang and Professor Li Zezhou, has achieved significant new advancements in exploring the formation mechanism of adiabatic shear bands in refractory high-entropy alloys. Their relevant research findings have been published in Acta Materialia, a prestigious journal in the field of metallic materials. The paper is aptly titled (Note: The original text missed the paper title, here it's kept as a placeholder for actual title addition).

Through in-situ monitoring techniques, this study has successfully captured the real-time mechanical properties, temperature variations, and deformation processes of two refractory high-entropy alloys, NbTaTiV and NbTaTiVW, under dynamic loading conditions. The research revealed that prior to the formation of shear bands, structural softening predominantly influenced the material behavior, outweighing the effects of thermal softening. It was found that the temperature increase observed was a consequence of energy dissipation following shear band formation, rather than being the primary trigger for its occurrence.

To substantiate this conclusion, the team conducted constrained dynamic deformation experiments. These experiments led to the successful observation of nanocrystal formation preceding the emergence of adiabatic shear bands. This observation provides direct experimental evidence supporting the theory that 'structural softening is the dominant factor in shear band formation.' By integrating microstructural analysis, the study comprehensively elucidated the formation pathways and underlying mechanisms of adiabatic shear bands in the two high-entropy alloys from the perspectives of thermodynamics, kinetics, and energy dissipation.

This research effectively demystifies the formation mechanism of adiabatic shear bands in refractory high-entropy alloys under high strain rates. It offers crucial theoretical insights for optimizing the dynamic properties of these alloys. Dr. He Jianye from BIT's School of Materials Science and Engineering served as the first author of the paper. Meanwhile, Professor Cheng Xingwang, Professor Li Zezhou, and Associate Professor Zhu Shengxin from the Institute of Advanced Structure Technology acted as the corresponding authors. Additionally, Professor Chen Haosen and Associate Professor Zeng Qinglei provided invaluable guidance in key technical aspects of the research.