Nanoindentation into FeCoNiCrCu high-entropy alloy: An atomistic study

The mechanical behaviours of FeCoNiCrCu high entropy alloys (HEAs) were studied via large-scale molecular dynamics (MD) simulations. A rigid indenter was applied in the indentation to investigate the microstructural evolution and mechanical properties of HEAs in terms of indentation force, Young's modulus, dislocation behaviours, and shear strain distributions. Effects of Cu precipitation on the mechanical properties of HEAs were discussed. The modulus calculated from simulations were inconsistent with experiments. The precipitation of Cu will increase the elastic modulus of the matrix, while the solution of Cu into the matrix can increase the work strengthening rate. The coherent interface of Cu precipitation can contribute to a high work strengthening rate, while the incoherent interface will lead to a lower deformation resistance.