A review on the dynamic-mechanical behaviors of high-entropy alloys

High-entropy alloys (HEAs) are a family of novel multi-principal alloys containing >4 principal elements in equimolar ratios or nearly-equimolar ratios. The unique multiple-principal compo-nents bring in the high configurational entropy or mixing entropy, and some unique micro-structures of HEAs. Consequently, many impressive properties of HEAs, including outstanding dynamical mechanical performance, have been reported successively. Under the instantaneous loading with high strain rates (epsilon >103 s-1), dynamic-deformation mechanisms of materials are different from the static one, and the relevant influencing factors are complicated. To reveal the relationship between the unique microstructures of HEAs and their dynamic-mechanical prop-erties, 76 articles published during the period of July 2015 to January 2023 have been reviewed in the present work. Firstly, the statistics and classification of all 61 reported HEAs are system-atically done in terms of their processing, experimental method, theoretical model, phases and microstructures as well as the dynamic-mechanical properties. Secondly, theoretical models and deformation mechanism are summarized. The effects of dislocation motion, twinning, and phase transformation behavior on dynamic deformation of HEAs are discussed thoroughly. The adiabatic-shear behavior and its effect on dynamic deformation are also considered. The differ-ences of dynamic-mechanical behavior as well as the relevant mechanisms between HEAs and traditional metallic materials are described. Finally, the potential application under dynamic loads of HEAs are demonstrated thoroughly. The present article additionally deals with the future research directions of dynamic-mechanical behaviors in order to develop novel high-performance HEAs.