A new hardness formula incorporating the effect of source density on indentation response: a discrete dislocation plasticity analysis
File(s)
Author(s)
Xu, Yilun
Balint, Daniel
Dini, Daniele
Type
Journal Article
Abstract
Planar discrete dislocation plasticity (DDP) calculations that simulate thin single crystal films bonded to a rigid substrate indented by a rigid wedge are performed for different values of film thickness and dislocation source density. As in prior studies, an indentation size effect (ISE) is observed when indentation depth is sufficiently small relative to the film thickness. The
dependence of the ISE on dislocation source density is quantified in this study, and a modified form of the scaling law for the dependence of hardness on indentation depth, first derived by Nix and Gao, is proposed, which is valid over the entire range of indentation depths and correlates the length scale parameter with the average dislocation source spacing. Nanoindentation experimental data from the literature are fitted using this formula, which further verifies the proposed scaling of indentation pressure on dislocation source density.
dependence of the ISE on dislocation source density is quantified in this study, and a modified form of the scaling law for the dependence of hardness on indentation depth, first derived by Nix and Gao, is proposed, which is valid over the entire range of indentation depths and correlates the length scale parameter with the average dislocation source spacing. Nanoindentation experimental data from the literature are fitted using this formula, which further verifies the proposed scaling of indentation pressure on dislocation source density.
Date Issued
2019-09-25
Date Acceptance
2019-06-14
Citation
Surface and Coatings Technology, 2019, 374, pp.763-773
ISSN
0257-8972
Publisher
Elsevier
Start Page
763
End Page
773
Journal / Book Title
Surface and Coatings Technology
Volume
374
Copyright Statement
© 2019 Elsevier B.V. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Grant Number
EP/N025954/1
Subjects
0306 Physical Chemistry (incl. Structural)
0912 Materials Engineering
0204 Condensed Matter Physics
Applied Physics
Publication Status
Published
Date Publish Online
2019-06-16