Nanoindentation of Gold and Gold Alloys by Molecular Dynamics Simulation

Abstract

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.

Department(s)

Physics

Research Center/Lab(s)

Center for High Performance Computing Research

Keywords and Phrases

Defects; Gold; Hardness; Nanoindentation; Nucleation; Stainless Steel; Classical Molecular Dynamics; Defect Nucleation; Dislocation Generation; Force Displacement; Molecular Dynamics Simulations; Nano-Indentation Hardness; Nucleation Process; Stacking Fault Energies; Molecular Dynamics

International Standard Serial Number (ISSN)

0921-5093

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2016 Elsevier Ltd, All rights reserved.

Publication Date

01 Jan 2016

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