Molecular dynamic simulation of crack propagation in nanocrystalline Ni containing different shapes and types of second phases

In order to investigate the crack propagation in the nanocrystalline Ni containing different types of impurities (Ag, Au, Cu, Pd), several molecular dynamics simulations were carried out using the embedded atom method (EAM). The crack was assumed in a (1 1 1)[1 0 0] system with 10,400 atoms. The impurities were considered in two different shapes of short and long cylinder. The impurities were introduced near the crack tip. To analyze the failure behavior, the strain energy density (G) and strain energy distributions near the crack tip were obtained and studied. The results show that when the shape of impurity is short cylinder, the rate of releasing energy during the crack propagation did not depend on the type of impurity. As for the long cylindrical impurity, palladium exhibited the maximum effect on G. (C) 2011 Elsevier B.V. All rights reserved.