Regensburg 2010 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 38: Mechanical Properties III

MM 38.2: Vortrag

Mittwoch, 24. März 2010, 16:45–17:00, H16

Interface fracture simulation in lamellar TiAl crystals — •Pavel Leiva Ronda, Karsten Durst, Farasat Iqbal, and Mathias Göken — Institute of General Material Properties, Department of Materials Science and Engineering, University Erlangen-Nürnberg, Germany

A microscale fracture simulation has been applied to study the toughening of lamellar TiAl crystals through interface mechanisms. The crack growth at the weak gamma -TiAl/ alpha2 -TiAl and gamma -TiAl/ gamma -TiAl lamellar interfaces has been simulated by means of a finite element method using a cohesive modelling approach. The elasticity for gamma and alpha2 phases is assumed to be anisotropic while the plasticity model considers a continuum material with a proper homogenization of the two phases lamellar system. In this sense, the constitutive plastic behaviour is described by a two-dimensional plane stress Hill’s model based on reported crystal plasticity calculations. Parametric studies have been performed to investigate the effect of cohesive parameters as the energy release rate and also the influence of residual stresses on the fracture behaviour. Furthermore, it has been analyzed the relationship between bulk and interface properties within the frame of the cohesive model for the TiAl lamellar crystals.