Enhanced dynamic mechanical properties of face-centered cubic CoCrFeNi-based high entropy alloy via coherent L12 nanoprecipitates

Abstract

It is highly challenging to achieve a combination of high strength, sufficient ductility, and excellent work hardening rate in face-centered cubic high-entropy alloys under high strain rates. In the study, we demonstrate that the presence of coherent nano-scale L1₂ precipitates can enhance the dynamic compressive yield strength by at least 57.43 % without compromising the ductility and strain hardening capacity at the strain rate ranging from 1000 to 4000 s⁻¹. The introduction of nano-scale L1₂ precipitates is not only impede effectively the movement of dislocation on the primary slip plane, but stimulate the dislocation cross slip and multiple slip system. Our finding provides a pathway for the design and preparation of face-centered cubic-based high entropy alloys with outstanding dynamic mechanical properties.