Fracture of nanoscale Cu/Ag bimaterials with an interface crack

Abstract

The fracture of nanoscale metallic bimaterials with an interface crack is investigated using atomistic simulations under uniaxial tensile loading conditions. Two Cu/Ag bimaterials with different crystal orientations are considered to examine the direction-dependent interface fracture behaviors. The effects of crack tip states on the fracture toughness and fracture behavior are also studied. The overall features for the selected models of both bimaterials are brittle; however, the fracture patterns are slightly different. Three methods were adopted to calculate the fracture toughness including atomistic simulations, linear elastic fracture mechanics, and Griffith theory. The results from different methods show good consistency because the models of the two bimaterials exhibit a linear elastic response under the applied tensile loading conditions. The scatter of the fracture toughness for the same bimaterials obtained from atomistic simulations is attributed to the different initial states of the models induced by the discrete nature of the materials on the atomic scale.