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

Institut für Theoretische und Angewandte Physik, Universität Stuttgart - Pfaffenwaldring 57, 70550 Stuttgart, Germany, EU

Corresponding author: frohmut.roesch@itap.physik.uni-stuttgart.de

Received: 8 December 2008
Accepted: 13 February 2009

Abstract

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.