Nanoindentation of gold and gold alloys by molecular dynamics simulation

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:651

Article

Li, Yangzhong¹  Goyal, Anuj¹  Chernatynskiy, Aleksandr¹  Jayashankar, Jay. S.²  Kautzky, Michael C.²  Sinnott, Susan B.¹  Phillpot, Simon R.¹ 

[1] Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA

[2] Seagate Technol, Bloomington, MN 55435 USA

关键词: Molecular dynamics;    Nanoindentation;    Hardness;    Stacking fault energy;   

DOI  :  10.1016/j.msea.2015.10.081

来源: Elsevier

【 摘 要 】

The nanoindentation hardnesses and stacking fault energies (SFE) for pure and alloyed Au are determined from classical molecular dynamics simulations. Rather than a traditional force-displacement dependence that is examined in many previous nanoindentation works, we analyze the hardness vs. force in this study, which shows features that allow us to distinguish defect nucleation processes from hardening processes. During nanoindentation, homogeneously nucleated defects interact to form V-shape lock structures, and finally form four-sided dislocations that are continuously released into the bulk, in a manner similar to the heterogeneous Frank-Read dislocation generation mechanism. Hardness in the alloy system is predicted to be critically controlled by the ease and frequency of nucleation of new defects. Consistent with previous simulation results, the difference of the unstable and stable SFE, rather than the stable SFE along, is found to be closely related to this nucleation process, and thus to hardness. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free