Introducing Laves phase strengthening into an ultrafine-grained equiatomic CrFeNi alloy by niobium addition

Abstract We propose a strategy to enhance the yield strength of an ultrafine-grained equiatomic CrFeNi alloy through the addition of niobium to form a Laves phase in a face-center-cubic (fcc) matrix. The fabricated CrFeNiNb0.158 alloy shows a high yield strength of 961 ± 10 MPa and a good ductility of 10.1 ± 0.9 %. The phase formation and strengthening mechanisms were analyzed by Hume-Rothery rules and quantitative estimation. The modulus mismatch between Laves phase and fcc matrix was found to be the main strengthening origin. This study provides significant insight into strengthening medium-/high-entropy alloys by introducing hard intermetallic compounds.