An investigation of the tensile deformation and failure of an epoxy/Cu interface using coarse-grained molecular dynamics simulations

In this study, a coarse-grained model is developed to describe the interatomic interactions between a cross-linked epoxy and a copper substrate. Based on this model, the tensile deformation and failure of an epoxy/Cu bimaterial is studied. Attention is given to the microstructural evolution near the epoxy/Cu interface, and its effects on the overall stress-strain behavior of the bimaterial. It is found that, under uniaxial strain, plastic deformation in the epoxy/Cu bimaterial is localized to a thin layer of epoxy next to the epoxy/Cu interface. This discovery enables the definition of an interfacial zone. Consequently, a cohesive zone model at the continuum level could potentially be constructed where the separation of the interface is given by the stretching of the interfacial zone computed from the coarse grain simulations.