Atomistic modeling of surface and grain boundary dislocation nucleation in FCC metals. (15th September 2022)

• Record Type: Journal Article
• Authors: Zhang, Yin; Ding, Kunqing; Stangebye, Sandra; Chen, Dengke; Kacher, Josh; Pierron, Olivier; Zhu, Ting
• Is Part Of: Acta materialia. Volume 237(2022)
• Publication Date: 2022-09-15
• Subjects: Grain boundary -- Dislocation nucleation -- Activation volume; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2022.118155
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: Dislocation nucleation plays a critical role in the plastic deformation of crystalline materials. However, it is challenging to predict the active mode and associated rate of dislocation nucleation under typical experimental loading conditions through molecular dynamics simulation due to timescale limitations. Here we use the free-end nudged elastic band method to determine the activation energies and activation volumes of dislocation nucleation in four typical face-centered cubic metals of Au, Al, Cu and Ni. We focus on the representative processes of surface and grain boundary dislocation nucleation. The atomistically determined activation volumes of these dislocation nucleation processes are larger than 10 b 3 (with b being the Burgers vector length) under typical experimental loading conditions. These results are compared with experimentally measured activation volumes in ultrafine-grained and nanocrystalline metals, thereby providing mechanistic insight into their rate-controlling deformation mechanisms. Graphical abstract: Image, graphical abstract