Journal ArticleDOI
Atomistic simulations of elastic deformation and dislocation nucleation during nanoindentation
Reads0
Chats0
TLDR
In this paper, a simulation study of the initial stages of indentation using the embedded atom method (EAM) is presented, and a comparison is made between atomistic simulations and continuum models for elastic deformation.Abstract:
Nanoindentation experiments have shown that microstructural inhomogeneities across the surface of gold thin films lead to position-dependent nanoindentation behavior [Phys. Rev. B (2002), to be submitted]. The rationale for such behavior was based on the availability of dislocation sources at the grain boundary for initiating plasticity. In order to verify or refute this theory, a computational approach has been pursued. Here, a simulation study of the initial stages of indentation using the embedded atom method (EAM) is presented. First, the principles of the EAM are given, and a comparison is made between atomistic simulations and continuum models for elastic deformation. Then, the mechanism of dislocation nucleation in single crystalline gold is analyzed, and the effects of elastic anisotropy are considered. Finally, a systematic study of the indentation response in the proximity of a high angle, high sigma (low symmetry) grain boundary is presented; indentation behavior is simulated for varying indenter positions relative to the boundary. The results indicate that high angle grain boundaries are a ready source of dislocations in indentation-induced deformation.read more
Citations
More filters
Journal ArticleDOI
Nanoindentation studies of materials
TL;DR: Nanoindentation has become a commonplace tool for the measurement of mechanical properties at small scales, but may have even greater importance as a technique for experimental studies of fundamental materials physics as discussed by the authors.
Journal ArticleDOI
Recent advances in single-asperity nanotribology
TL;DR: In this article, the authors review recent advances in the experimental, theoretical and computational studies of nanotribology and focus on the latest developments in atomic force microscopy and molecular dynamics simulations and their application to the study of single-asperity contact.
Journal ArticleDOI
Indentation across size scales and disciplines: Recent developments in experimentation and modeling
TL;DR: Indentation is a remarkably flexible mechanical test due to its relative experimental simplicity as discussed by the authors, and the ease of implementation has made indentation a ubiquitous research tool for a number of different systems across size scales (nano to macro) and scientific/engineering disciplines.
Journal ArticleDOI
A new view of the onset of plasticity during the nanoindentation of aluminium
Andrew M. Minor,S. A. Syed Asif,Zhi-Wei Shan,Eric A. Stach,Edward Cyrankowski,Thomas J. Wyrobek,Oden L. Warren +6 more
TL;DR: Direct evidence is reported that plasticity in a dislocation-free volume of polycrystalline aluminium can begin at very small forces, remarkably, even before the first sustained rise in repulsive force, contrary to earlier assumptions that a dislocated-freevolume is necessary to achieve shear stresses near the theoretical shear strength of the material.
Journal ArticleDOI
Quantitative insight into dislocation nucleation from high-temperature nanoindentation experiments.
TL;DR: The development and application of high-temperature nanoindentation testing, and the introduction of statistical methods to quantitatively evaluate data, suggest an unexpected picture of incipient plasticity that involves heterogeneous nucleation sites, and which has not been anticipated by atomistic simulations.
References
More filters
Journal ArticleDOI
An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments
Warren C. Oliver,George M. Pharr +1 more
TL;DR: In this paper, the authors used a Berkovich indenter to determine hardness and elastic modulus from indentation load-displacement data, and showed that the curve of the curve is not linear, even in the initial stages of the unloading process.
Journal ArticleDOI
Embedded-atom method: Derivation and application to impurities, surfaces, and other defects in metals
Murray S. Daw,Michael I. Baskes +1 more
TL;DR: In this paper, the authors derived an expression for the total energy of a metal using the embedding energy from which they obtained several ground-state properties, such as the lattice constant, elastic constants, sublimation energy, and vacancy-formation energy.
Journal ArticleDOI
The relation between load and penetration in the axisymmetric Boussinesq problem for a punch of arbitrary profile
TL;DR: In this article, a solution of the axisymmetric Boussinesq problem is derived from which are deduced simple formulae for the depth of penetration of the tip of a punch of arbitrary profile and for the total load which must be applied to the punch to achieve this penetration.
Journal ArticleDOI
Embedded-atom-method functions for the fcc metals Cu, Ag, Au, Ni, Pd, Pt, and their alloys.
TL;DR: A consistent set of embedding functions and pair interactions for use with the embedded-atom method was determined empirically by fitting to the sublimation energy, equilibrium lattice constant, elastic constants, and vacancy-formation energies of the pure metals and the heats of solution of the binary alloys as discussed by the authors.
Journal ArticleDOI
Dislocation nucleation and defect structure during surface indentation
TL;DR: In this paper, an atomistic imaging of dislocation nucleation during displacement controlled indentation on a passivated surface is presented, where defects are located and imaged by local deviations from centrosymmetry.