Mechanical Behavior of Nanotwinned Cu–Ag Alloys with Solute Atomic Gradient Analysis Under the Influence of Twinning Spacing

Abstract

To investigate the impact of Twinning Boundary Spacing (TBS) on the mechanical characteristics and deformation behavior of nanotwinned Cu–Ag alloys with solute gradient segregation structure during nanoindentation, Voronoi’s method is utilized to create a nanotwinned Cu–Ag alloy model with solute gradient segregation structure. Then, the indentation process of the indenter pressed into the model with varying TBS is simulated using the Molecular Dynamics (MD) simulation, yielding depth-stress curves of the corresponding indenter. According to the findings, yield stresses are lower in Cu–Ag alloys with smaller twin spacing. Grain boundary activities play a governing role in the plastic deformation of the matrix during the small deformation stage, although dislocations also play a part. Grain boundaries have less of an impact on material deformation during the big deformation stage, and dislocations are primarily responsible for the matrix’s plastic deformation. The stacking faults and deformation twin are more prone to occur inside grains with higher solute-atom concentrations compared to grain boundaries with lower solute-atom concentrations.