Strain-rate effect upon the tensile behavior of CoCrFeNi high-entropy alloys

Abstract

High-entropy alloys could replace conventional materials in critical load-bearing applications, owing to their excellent mechanical properties. Supported by X-ray diffraction, microstructure analysis and tensile testing, the mechanical response of CoCrFeNi HEAs to varying strain rates was investigated. The alloys were found to be a single-phase face-centered cubic solid solution. Their tensile strength and ductility increased with rising strain rate. The dominant deformation mechanism of the high-entropy alloy was observed to shift from the dislocation motion at the lower strain rates to stacking faults at the higher strain rates. The CoCrFeNi high-entropy alloys exhibited greater hardness following tensile deformation with higher strain rates.