Discrete dislocation simulation of nanoindentation: Indentation size effect and the influence of slip band orientation

Kreuzer, H.; Pippan, Reinhard

doi:10.1016/j.actamat.2007.01.021

Cited by 37 publications

(25 citation statements)

References 13 publications

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“…[24] In other words, it is yet to be unequivocally established as to which one of these is the best one to explain ISE in brittle solids in general and that in glass, in particular. [4] Recent two-dimensional discrete dislocation modeling work [55] on ISE has shown that, compared to a case where the slip bands are oriented parallel to the surface, a less pronounced decrease of the hardness with increasing indentation depth is observed for the nonparallel slip band orientation. The origin of the different effects was partly linked to the discrete nature of plasticity that operates in the domain of the nanometric scale regime of microstructure.…”

Section: Resultsmentioning

confidence: 98%

Loading Rate Effect on Nanohardness of Soda-Lime-Silica Glass

Chakraborty

Dey

Mukhopadhyay

2010

Metall Mater Trans A

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To understand how hardness, the key design parameter for applications of brittle solids such as glass concerning contact deformation, is affected by loading rate variation, nanoindentation with a Berkovich tip was used to measure the nanohardness of a 330-lm-thick soda-lime-silica glass as a function of loading rate (1 to 1000 mNAEs À1 ). The results showed for the very first time that, with variations in the loading rate, there was a 6 to 9 pct increase in the nanohardness of glass up to a threshold loading rate (TLR), whereafter it did not appreciably increase with further increase in loading rate. Further, the nanohardness data showed an indentation size effect (ISE) that obeyed the Meyer's law. These observations were explained in terms of a strong shear stress component developed just beneath the nanoindenter and the related shear-induced deformation processes at local microstructural scale weak links. The significant or insignificant presence of shear-induced serrations in load depth plots and corresponding scanning electron microscopic evidence of a strong or mild presence of shear deformation bands in and around the nanoindentation cavity supported such a rationalization. Finally, a qualitative picture was developed for different deformation processes induced at various loading rates in glass.

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Section: Resultsmentioning

confidence: 98%

Loading Rate Effect on Nanohardness of Soda-Lime-Silica Glass

Chakraborty

Dey

Mukhopadhyay

2010

Metall Mater Trans A

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“…The work reported in [30][31][32] primarily focused on size effects in nano-indentation by sinusoidal and wedge-shaped indenters on crystals characterised by a low density of sources. The work was devoted to the investigation of the effect of microstructure, including nucleation source density, and number and orientation of pre-defined slip planes, on the indentation pressure [33][34][35]. Furthermore, the effect of indenter shape on the indentation pressure was studied using numerical simulations [36,37], which have also been successfully corroborated by experimental data [17].…”

Section: Introductionmentioning

confidence: 99%

A method of coupling discrete dislocation plasticity to the crystal plasticity finite element method

Balint

Dini

2016

Modelling Simul. Mater. Sci. Eng.

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A method of concurrent coupling of planar discrete dislocation plasticity (DDP) and a crystal plasticity finite element (CPFE) method was devised for simulating plastic deformation in large polycrystals with discrete dislocation resolution in a single grain or cluster of grains for computational efficiency; computation time using the coupling method can be reduced by an order of magnitude compared to DDP. The method is based on an iterative scheme initiated by a sub-model calculation, which ensures displacement and traction compatibility at all nodes at the interface between the DDP and CPFE domains. The proposed coupling approach is demonstrated using two plane strain problems: (i) uniaxial tension of a bi-crystal film and (ii) indentation of a thin film on a substrate. The latter was also used to demonstrate that the rigid substrate assumption used in earlier DDP studies is inadequate for indentation depths that are large compared to the film thickness, i.e. the effect of the plastic substrate modelled using CPFE becomes important. The coupling method can be used to study a wider range of indentation depths than previously possible using DDP alone, without sacrificing the indentation size effect regime captured by DDP. The method is general and can be applied to any problem where finer resolution of dislocation mediated plasticity is required to study the mechanical response of polycrystalline materials, e.g. to capture size effects locally within a larger elastic/plastic boundary value problem.

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“…It is well known that a wide variety of materials (e.g., metallic, ceramic, and quasi-crystalline) [10][11][12][13] exhibit ISE. Although numerous explanations have been proposed, [14][15][16][17][18][19][20][21][22][23][24][25] the basic cause of ISE in structural ceramics (e.g., polycrystalline alumina) is yet to be unequivocally established [12] because all of such explanations [14][15][16][17][18][19][20][21][22] or models [23][24][25] for ISE have their own limitations. [13,26] Thus, the basic objective of the present work was to use the nanoindentation technique to evaluate nanohardness of shock-recovered fragments of a coarse-grain (10 lm), high-density (3.978 gm cc -1 ) alumina obtained after a carefully conducted flyer-plate shock experiment, [27] and to examine if the nanohardness was similar to or degraded in comparison with that of the as-sintered alumina ceramics.…”

Section: Introductionmentioning

confidence: 99%

Nanohardness of Sintered and Shock Deformed Alumina

Chakraborty

Dey

Mukhopadhyay

et al. 2011

Metall Mater Trans A

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To understand how high-strain rate, flyer-plate impact affects the nanohardness of a coarse (~10 lm) grain, high-density (~3.978 gm cc -1 ) alumina, load controlled nanoindentation experiments were conducted with a Berkovich indenter on as-sintered disks and shock-recovered alumina fragments obtained from an earlier flyer-plate shock impact study. The nanohardness of the shock-recovered alumina was much lower than that of the as-sintered alumina. The indentation size effect was severe in the shock-recovered alumina but only mild in the as-sintered alumina. Extensive additional characterization by field emission scanning electron microscopy, transmission electron microscopy, and analysis of the experimental load depth data were used to provide a new explanation for the presence of strong indentation size effect in the shockrecovered alumina. Finally, a qualitative model was proposed to provide a rationale for the whole scenario of nanoindentation responses in the as-sintered and shock-recovered alumina ceramics.

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Discrete dislocation simulation of nanoindentation: Indentation size effect and the influence of slip band orientation

Cited by 37 publications

References 13 publications

Loading Rate Effect on Nanohardness of Soda-Lime-Silica Glass

Loading Rate Effect on Nanohardness of Soda-Lime-Silica Glass

A method of coupling discrete dislocation plasticity to the crystal plasticity finite element method

Nanohardness of Sintered and Shock Deformed Alumina

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