Fracture behavior transition in (001) cracked metal nanoplates induced by the surface effect

In this study, we show that the fracture mode of (001) cracked metal nanoplates is strongly dependent on the size through molecular dynamics simulations. Cracked nanoplates with smaller sizes exhibit an elastic instability-dominant fracture followed by a ductile behavior, whereas larger cracked nanoplates exhibit a brittle fracture. A brittle fracture is caused by an embedded crack, whereas the elastic instability-dominant fracture is due to a failure of the nanoplate by elastic instability, which is influenced by the surface effect. We provide numerical and theoretical evidence to show that the transition in the fracture behavior of a cracked metal nanoplate is due to the competition between the crack and the free surfaces.