Strengthening of ultrafine-grained equiatomic CoCrFeMnNi high-entropy alloy by nitrogen addition

Abstract

A design of precipitate-containing, ultrafine-grained equiatomic CoCrFeMnNi high-entropy alloy with the addition of nitrogen was introduced. The introduction of nitrogen led to the formation of Cr- and N-rich precipitate of Cr2N on the low temperature-annealed N-CoCrFeMnNi. It was noticed that the presence of nitrogen in N-CoCrFeMnNi suppressed the formation of r-phase precipitate generally observed in low temperature-annealed CoCrFeMnNi system. Furthermore, it was observed that the addition of nitrogen could be utilized as a viable method in enhancing the mechanical properties of ultrafine-grained CoCrFeMnNi matrix, in which the addition of nitrogen successfully led to an improved yield strength and ultimate tensile strength of the ultrafine-grained CoCrFeMnNi system. (C) 2019 Elsevier B.V. All rights reserved.