Berlin 2015 – wissenschaftliches Programm
MM 28.34: Poster
Dienstag, 17. März 2015, 18:30–20:30, Poster E
Influence of heterogeneities on the fracture behavior of NiAl — •Polina N. Baranova, Johannes J. Möller, and Erik Bitzek — Department of Material Sciences & Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Germany
The fracture of a brittle solid is crucially determined by material heterogeneities directly at the crack front where the stress field diverges. Here, the usual homogenization strategies of continuum mechanics are no longer applicable, and currently there exist no consistent theory that relates local fluctuations in elastic properties, cohesion, toughness, or stress fields to the local fracture behavior and macroscopic failure criteria. Here we present atomistic simulations of static and propagating cracks in the Ni-Al system to study the influence of heterogeneities on the fracture behavior. Heterogeneities on the atomic scale were introduced by varying the composition of B2 NiAl, whereas voids and Ni-precipitates served as mesoscale heterogeneities. The simulation results are compared to experiments and discussed in the framework of linear elastic fracture mechanics for heterogeneous media.