Understanding the Effect of Mo Concentration on the Strength of AlCoCrFeMo High-Entropy Alloy Using Atomistic Simulations

Abstract

Abstract High-entropy alloys (HEAs) represent a new class of advanced metallic alloys that have gained significant interest. They offer a unique combination of mechanical, thermal, and functional properties, making HEAs ideal for various industrial applications. One such alloy is the recently developed equiatomic body-centred cubic phase AlCoCrFeMo. In particular, thermally sprayed AlCoCrFeMo coatings have gained wide interest due to their exceptional mechanical properties compared to common industrial steel. In the current study, the effect of Mo concentrations on the strength of single crystal AlCoCrFeMo HEA was investigated using molecular dynamics simulation and the phase stability of the alloy was studied using polyhedral template matching. Our results indicate that the local lattice distortion of the alloy is not significantly related to Mo concentration. The yield strength of AlCoCrFeMo HEA obtained through tensile loading, was found to increase with Mo concentration, at a molar ratio of Mo higher than 0.5. Investigation of the deformation behavior of the HEA revealed that bands with high shear strains evolved during plastic deformation. The formation of shear bands after the yield point elucidated the softening exhibited by the material due to localized deformation. These findings provide guidance for tailoring the mechanical properties of AlCoCrFeMo HEA by adjusting Mo concentrations, offering new avenues for designing functional coating materials.