Strengthening of a CoCrFeNiMn-Type High Entropy Alloy by Regular Arrays of Nanoprecipitates

Abstract

In this paper, we report microstructure and mechanical properties evolution of the CoCrFeNiMn-type high entropy alloy, containing small amounts of Al and C, during cold rolling and subsequent annealing at 700-1100°C. In the initial as-cast condition the alloy has coarse-grained single face-centered cubic (fcc) phase structure. Cold rolling and annealing substantially refine fcc grains; in addition M23C6 type carbides appear. After annealing at relatively low temperatures (≤900°C), these particles are arranged in characteristic arrays aligned with rolling directions. The specific microstructure of the thermomechanically processed alloy is suggested to be the reason of the balanced combination of tensile strength and ductility.