Minimum Energy Motion and Core Structure of Pure Edge and Screw Dislocations in Aluminum

Journal of Computational Science and Technology

Yoji SHIBUTANI²  Yoshiyuki KAJI¹  Tomohito TSURU¹ 

[1] Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency;Department of Mechanical Engineering, Osaka University

关键词: Edge/Screw Dislocation;    Peierls Potential;    Aluminum;    Nudged Elastic Band Method;   

DOI  :  10.1299/jcst.4.185

学科分类：地球科学(综合)

来源: Japan Academy

【 摘 要 】

References(38)Cited-By(2)The minimum energy motions of pure edge and screw dislocations in aluminum were investigated by atomistic transition state analysis. While the Peierls-Nabarro model and its modifications duplicate the essential nature of a dislocation within a crystalline lattice, the atomic-level relaxation of the dislocation core should be considered to estimate the minimum energy barrier. The relaxed atomic structure within and around the dislocation core is derived from the material’s inherent intrinsic properties and is therefore difficult to solve solely by simple analytical models. In this study, the minimum energy barriers and core structures for the quasi-static motions of pure edge and screw dislocations were investigated by the parallelized nudged elastic band method with the embedded atom method potential. We found that the local potential energy is distributed asymmetrically around the dislocation line for the most stable state and that it is bilaterally symmetrical at the transition state of the dislocation motion. The short-ranged structural relaxation of the core rearrangement as well as the wide-ranging elastic stress field is of great importance in realistic dislocation motion.

【 授权许可】

Unknown