Alloy strengthening toward improving mechanical and tribological performances of Cu_xNi_100−x/Ta nano multilayer materials

Alloy strengthening via introducing Ni atoms into Cu monolayer of Cu/Ta nano multilayer materials (NMMs) is used to enhance mechanical and tribological properties. Molecular dynamics simulations indicate that the introduction of solid-solution Ni atoms suppresses the dislocation multiplication and glide, leading to higher hardness, better tribological performances, and stronger deformation resistance for Cu_xNi_100−x/Ta NMMs. The deformation resistance in nanoindentation is mainly determined by hardness and interlayer interface, where the interface acts as dislocation barrier and emission source to restrain main compression stress within about three monolayers. The resistance against friction-induced deformation relies on the comprehensive properties of strengthening monolayers and alloying interfaces, which induces further removal of Ta atoms. The atom-scale insights on the NMMs strengthening and the corresponding deformation mechanism are helpful for designing new wear-resistant materials.