Brittle fracture in a complex metallic compound from an atomistic viewpoint: NbCr2, a case study

Material-specific atomistic aspects of brittle fracture are studied for the first time for a complex metallic compound with realistic embedded-atom-method potentials. Crack propagation occurs on an atomic level by a successive rupture of cohesive bonds. In many theoretical models of fracture, however, a coarse-grained approach is applied and the explicit influence of the discrete nature of matter is not taken into account. In this paper, numerical experiments on the complex metallic compound NbCr2 are presented to illustrate why it is necessary to perform atomistic simulations to understand the details of fracture behaviour: the number, strength and orientation of bonds approached by a crack determine whether, where and how it propagates. Copyright (C) EPLA, 2009