|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Advances in Multi-Principal Elements Alloys X
||Jerky dislocation motion in multi-principle element alloys: From atomic Peierls stress to dislocation mobility
||Daniel Utt, Subin Lee, Yaolong Xing, Hyejin Jeong, Alexander Stukowski, Sang Ho Oh, Gerhard Dehm, Karsten Albe
|On-Site Speaker (Planned)
Dislocations in multi-principle element alloys (MPEAs) repeatedly encounter pinning during glide, leading to jerky dislocation motion. However, the origin of individual pinning points in these concentrated random alloys is a matter of debate. We investigate the origin of dislocation pinning in the prototypical Cantor (CoCrFeMnNi) MPEA and its subsystem using a combination of experiment and simulation. In-situ transmission electron microscopy studies reveal a jagged glide motion under external loading, even in the absence of elemental clustering. Our large-scale atomistic simulations reproduce the jerky dislocation motion and allow for a determination of an atomistic descriptor linking dislocation pinning sites to a local Peierls barrier. Repeated pinning of the dislocation line can be linked to local fluctuations in the atomic scale Peierls friction. We demonstrate that the spatial density of high local Peierls barriers is proportional to the critical stress required to initiate dislocation glide and inversely linked to the dislocation mobility.
||High-Entropy Alloys, Mechanical Properties, Computational Materials Science & Engineering