Fracture experiments on symmetric-tilt grain boundaries in Cu are interpreted using the Peierls-Nabarro continuum model of dislocation nucleation as a starting point. Good agreement is found only when the continuum model is modified according to the results of atomistic simulations. The same experiments are also reproduced by direct Molecular Dynamics simulations of fracture propagation and dislocation emission from a microcrack placed in the interface plane of the symmetric-tilt (221)(221) grain boundary in fcc Cu. Direction-dependent fracture response is observed, namely the microcrack advancing by brittle fracture along the [114̄] direction and being blunted by dislocation emission along the opposite [1̄1̄4] direction. Moreover, the simulations allow us to establish important differences with respect to the continuum-model predictions due to the shielding of the stress field at the crack-tip and to the presence of the residual stress at the interface.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
Cleri, F., Phillpot, S. R., & Wolf, D. (1999). Atomistic simulations of integranular fracture in symmetric-tilt grain boundaries. Interface Science, 7(1), 45 - 55. https://doi.org/10.1023/A:1008773913030