The crucial role of chemistry on mobile properties of dislocation

Abstract

Dislocation–solute interactions are ubiquitous in solids, yet their dual nature in strengthening or softening the material is not well understood. Results of a novel concurrent multiscale approach reveal that the local environment of W solutes in Ta has a dramatic effect both on the dislocation mobility and slip paths. W solutes can enhance or reduce the mobility, and may result in spontaneous dislocation glide. The atomistic mechanism responsible for the dual nature of solutes is elucidated.

Keywords:

• multiscale simulation
• dislocations
• impurity
• chemistry effect

Acknowledgements

We acknowledge valuable discussions with V. Vitek. This research was supported by a DOE NERI grant DE-FC07-06ID14748, NSF-PREM grant DMR-00116566, US Army grant W911NF-04-1-0058, and DOE SciDAC grant DE-FC02-06ER25791.