|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Fracture Properties and Residual Stresses in Small Dimensions
||Atomistic Simulations of Crack Nucleation and Propagation along Grain Boundaries
||Erik Bitzek, Johannes J. Möller
|On-Site Speaker (Planned)
Understanding the influence of the grain boundary structure and the relative orientation of the slip systems to the GB/crack plane on crack initiation and propagation is key to modeling intergranular fracture in polycrystalline materials. Here, atomistic simulations are ideally suited to investigate the details of grain boundary fracture. However, most of the simulations are currently performed using quasi-2D setups with straight crack fronts on perfect GBs.
Here we present the results of large-scale 3D atomistic simulations using EAM potentials for various bcc metals. Crack nucleation by dislocation pile-ups were compared to crack nuclei formed by agglomerated vacancies. Crack propagation was studied for penny-shaped GB cracks, which showed distinct differences to the behavior of long, straight cracks. Further simulations revealed the influence of absorbed dislocation contents on intergranular fracture. The results are discussed in the context of fracture and fatigue of nanoscale objects as well as crack nuclei in bulk metals.