Theoretical study of the mechanical properties of CrFeCoNiMox (0.1 ≤ x ≤ 0.3) alloys

Abstract

Based on exact muffin-tin orbitals (EMTO) and coherent potential approximation (CPA), we investigate the effects of Mo content on the mechanical properties of CrFeCoNiMo_x (0.1 ≤ x ≤ 0.3) high-entropy alloys (HEAs) with a face-centered-cubic (fcc) crystal structure; relevant physical parameters are calculated as a function of Mo content. The results indicate that the theoretical predictions of lattice constant, elastic constants, shear modulus, and Young's modulus are in good agreement with the available experimental data, which proves the validity of the applied approach. CrFeCoNiMo_0.26 HEA has better ductility and plasticity with respect to other HEAs with different Mo contents because it has the minimum elastic moduli and Vickers hardness, and has the maximum Pugh's ratio and anisotropy factors, etc. CrFeCoNiMo_0.2 HEA has better plasticity compared with CrFeCoNiMo_0.1 and CrFeCoNiMo_0.3 HEAs due to its minimum energy factor and maximum dislocation width. Screw dislocation is more likely to nucleate in CrFeCoNiMo_x (0.1 ≤ x ≤ 0.3) HEAs than edge dislocation. The present studies are helpful to explore the excellent mechanical properties of CrFeCoNiMo_x (0.1 ≤ x ≤ 0.3) HEAs during experiments.