Exploring the Influence of the Coarse Grain Size and Ag Atomic Content on Mechanical Properties of Bimodal Nanotwinned Cu-Ag Alloys

The deformation mechanism of bimodal nanotwinned (NT) Cu-Ag alloy with grain boundary segregation has been simulated by the molecular dynamics method. The equidistance scaling method has been used to generate a grain boundary affect zone. Construction of a bimodal NT Cu-Ag alloy model was achieved by implanting coarse NT grains in an ultrafine grain matrix. Uniaxial tensile experiments were carried out on NT Cu-Ag alloys to explore the deformation mechanism of Cu-Ag alloys in different strain conditions. By analyzing atomic stress–strain images obtained by uniaxial tensile testing, the strength of the bimodal NT Cu-Ag alloy models has been discovered to have a relationship with the coarse grain size and Ag atom concentration. A detailed description is given based on the dislocation activity and the associated deformation mechanism. The properties of the bimodal NT Cu-Ag alloys have been analyzed by surveying the intrinsic dislocation activity of the models.