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Structural Investigation of Size Effects in Plasticity using Indentation ...

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B<br />

The deformation-<strong>in</strong>duced zone below<br />

large and shallow nano<strong>in</strong>dentations – A<br />

comparative study us<strong>in</strong>g EBSD and TEM<br />

M. Rester, C. Motz and R. Pippan<br />

Erich Schmid Institute <strong>of</strong> Materials Science, Austrian Academy <strong>of</strong> Sciences,<br />

A–8700 Leoben, Austria<br />

Abstract<br />

The paper addresses the comparison <strong>of</strong> the deformation-<strong>in</strong>duced zone beneath<br />

nano<strong>in</strong>dentations obta<strong>in</strong>ed by electron backscatter diffraction (EBSD) and transmission<br />

electron microscopy (TEM). S<strong>in</strong>ce EBSD is associated with resolutional<br />

restrictions, especially at very small scan sizes, it is not known how accurate the<br />

deformed volume beneath the impr<strong>in</strong>ts can be characterized. For these purposes,<br />

cross-sectional EBSD and TEM samples <strong>of</strong> nano<strong>in</strong>dentations were fabricated by<br />

means <strong>of</strong> a focused ion beam (FIB) workstation, analyzed, and subsequently compared<br />

among each other. For large <strong>in</strong>dentations as well as for shallow ones, a very<br />

good agreement <strong>of</strong> the determ<strong>in</strong>ed zones was found. The results <strong>of</strong> the EBSD and<br />

TEM experiments were also used to characterize the deformation-<strong>in</strong>duced volume.<br />

In the EBSD maps <strong>of</strong> the large <strong>in</strong>dentations, strongly conf<strong>in</strong>ed deformation patterns<br />

were found while for the shallow <strong>in</strong>dentations the observed patterns are ambiguous.<br />

The TEM micrographs and additionally performed selected area electron diffraction<br />

(SAED) support these facts and give <strong>in</strong>sight <strong>in</strong>to the dislocation structure <strong>of</strong> the<br />

deformation zone.<br />

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