Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1503109 | Scripta Materialia | 2006 | 5 Pages |
The atomic processes underlying cyclic fatigue was investigated in a metallic glass using molecular-dynamics simulations. A simple four component Lennard–Jones model was used to characterize the behavior of the free volume during deformation. The deformation behavior observed was typical of that seen experimentally, involving both elastic and plastic strains, load history dependence and strain rate sensitivity. Changes in free volume and excess strain were monitored during deformation to demonstrate how the stress state affects the distribution of free volume and how regions with excess free volume preferentially deform. Simulation results indicated that free volume levels were increased and localized during deformation, a process that was greatly accelerated under cyclic loading conditions. The results are used to rationalize the poor fatigue properties commonly reported for metallic glasses.