Title

Nanoindentation measurements of the mechanical properties of polycrystalline Au and Ag thin films on silicon substrates: Effects of grain size and film thickness

Authors

Authors

Y. F. Cao; S. Allameh; D. Nankivil; S. Sethiaraj; T. Otiti;W. Soboyejo

Comments

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Abbreviated Journal Title

Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process.

Keywords

nanoindentation; fcc thin films; hardness; Young's modulus; Hall-Petch; effects; thickness effect; SENSING INDENTATION EXPERIMENTS; STRAIN GRADIENT PLASTICITY; ELASTIC-MODULUS; SINGLE-CRYSTALS; CONTACT AREA; DEFORMATION; SURFACES; TEMPERATURE; DEPOSITION; BEHAVIOR; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering

Abstract

This paper presents the results of nanoindentation experimental studies of the contact-induced deformation in An and Ag thin films. The paper examines the effects of film thickness and substrate deformation restraint on the mechanical properties of electron beam (e-beam) deposited An and Ag films. Following a brief description of film microstructure, surface topography, and contact-induced pile-up deformation, film mechanical properties (hardness and Young's modulus) were determined using nanoindentation techniques. The indentation size effects (ISE) observed in films with different thicknesses were explained using a mechanism-based strain gradient (MSG) theory. The intrinsic film yield strengths and hardnesses extracted from the MSG theory are shown to exhibit classical Hall-Petch dependence on the inverse square root of the average film grain size. Displacement bursts were also found to occur in Ag films at indentation load levels of 100 mu N. These were attributed to the initial onset of dislocation slip activity, when the shear stress exceeds the estimated theoretical shear strengths of the materials. (c) 2006 Elsevier B.V. All rights reserved.

Journal Title

Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing

Volume

427

Issue/Number

1-2

Publication Date

1-1-2006

Document Type

Article

Language

English

First Page

232

Last Page

240

WOS Identifier

WOS:000239019000030

ISSN

0921-5093

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