TY - JOUR
T1 - Molecular dynamics simulations of intergranular fracture in UO2 with nine empirical interatomic potentials
AU - Zhang, Yongfeng
AU - Millett, Paul C.
AU - Tonks, Michael R.
AU - Bai, Xian Ming
AU - Biner, S. Bulent
N1 - Funding Information:
The authors gratefully acknowledge the support of the DOE Nuclear Energy Advanced Modeling and Simulation (NEAMS) Program, under the Fuels Integrated Performance and Safety Code (IPSC) project with work Package No. FTLA11MS0603. This manuscript has been authored by Battelle Energy Alliance, LLC under Contract No. DE-AC07-05ID14517 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.
PY - 2014/9
Y1 - 2014/9
N2 - The intergranular fracture behavior of UO2 was studied using molecular dynamics simulations with a bicrystal model. The anisotropic fracture behavior due to the different grain boundary characters was investigated with the 〈100〉 symmetrical tilt Σ5 and the 〈110〉 symmetrical tilt Σ3 ({1 1 1} twin) grain boundaries. Nine interatomic potentials, seven rigid-ion plus two core-shell ones, were utilized to elucidate possible potential dependence. Initiating from a notch, crack propagation along grain boundaries was observed for most potentials. The Σ3 boundary was found to be more prone to fracture than the Σ5 one, indicated by a lower energy release rate associated with the former. However, some potential dependence was identified on the existence of transient plastic deformation at crack tips, and the results were discussed regarding the relevant material properties including the excess energies of metastable phases and the critical energy release rate for intergranular fracture. In general, local plasticity at crack tips was observed in fracture simulations with potentials that predict low excess energies for metastable phases and high critical energy release rates for intergranular fracture.
AB - The intergranular fracture behavior of UO2 was studied using molecular dynamics simulations with a bicrystal model. The anisotropic fracture behavior due to the different grain boundary characters was investigated with the 〈100〉 symmetrical tilt Σ5 and the 〈110〉 symmetrical tilt Σ3 ({1 1 1} twin) grain boundaries. Nine interatomic potentials, seven rigid-ion plus two core-shell ones, were utilized to elucidate possible potential dependence. Initiating from a notch, crack propagation along grain boundaries was observed for most potentials. The Σ3 boundary was found to be more prone to fracture than the Σ5 one, indicated by a lower energy release rate associated with the former. However, some potential dependence was identified on the existence of transient plastic deformation at crack tips, and the results were discussed regarding the relevant material properties including the excess energies of metastable phases and the critical energy release rate for intergranular fracture. In general, local plasticity at crack tips was observed in fracture simulations with potentials that predict low excess energies for metastable phases and high critical energy release rates for intergranular fracture.
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U2 - 10.1016/j.jnucmat.2014.05.034
DO - 10.1016/j.jnucmat.2014.05.034
M3 - Article
AN - SCOPUS:84902143762
SN - 0022-3115
VL - 452
SP - 296
EP - 303
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
IS - 1-3
ER -