|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Computational Design and Simulation of Materials (CDSM 2018): Atomistic Simulations
||A Random Walk Model of Screw Dislocation Cross-slip in Face-centered Cubic Solid Solution Alloys
||Wolfram G Nöhring, William A Curtin
|On-Site Speaker (Planned)
||William A Curtin
The activation barrier for screw dislocation cross-slip in FCC solid solution alloys is controlled by local solute fluctuations . A model for the activation energy distribution of short (40b length) dislocations has been derived . Here, a model for long (100 nm to 1 μm long) dislocations is presented. Cross-slip is modeled as a one-dimensional random walk where each step corresponds to movement of a 1b segment from the glide to the cross-slip plane. Associated with each step is a random change in solute binding energies, plus a deterministic energy during formation of the initial constriction. The model reproduces the activation energy distribution of short dislocations. It is then used to predict the distribution, and its sensitivity to stress, for long dislocations. Results show that cross-slip is controlled by low activation barriers that are well below the average value.
 Nöhring, W.G.; Curtin, W.A. Acta Materialia 2017, 128, 135-148.
||Planned: Supplemental Proceedings volume