|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Advanced High-Strength Steels
||Molecular Dynamics Simulations of the Interaction of Helium Clusters with Grain Boundaries and Dislocations bcc Iron
||Tegar Wicaksono, Yu Yue, Matthias Militzer
|On-Site Speaker (Planned)
Solute atoms and precipitates significantly affect dislocation glide and grain boundary migration in alloys. Models for solute solution strengthening and solute drag as well as precipitation strengthening and particle pinning are well established. The intermediate case of solute clusters has, however, not yet been fully explored despite its technologically importance, e.g. embrittlement of irradiated steel reactors due to helium (He) clusters. In this work, the interplay between He segregation, He cluster formation and dislocation glide as well as curvature-driven grain boundary migration in bcc iron (Fe) has been investigated using molecular dynamics simulations. The restraining force on grain boundary migration increases with cluster size via a pinning mechanism. Similarly, the critical resolved shear stress for dislocation glide increases with the size of the He clusters. Phenomenological models for cluster pinning and strengthening are proposed based on these simulations results.
||Planned: Supplemental Proceedings volume