The deformation-induced zone below large and shallow nanoindentations: A comparative study using EBSD and TEM

Abstract

A comparison is made between the deformation-induced zone beneath nanoindentations obtained by Electron Backscatter Diffraction (EBSD) and Transmission Electron Microscopy (TEM). Since there are resolutional limitations associated with EBSD, especially at very small scan sizes, it is not known how accurately the deformed volume beneath the imprints can be characterized. To aid in answering this question, cross-sectional EBSD and TEM samples of nanoindentations were fabricated by means of a Focused Ion Beam (FIB) workstation, analyzed, and subsequently compared with each other. For large indentations as well as for shallow ones, agreement of the determined zones was found. The results of the EBSD and TEM experiments were also used to characterize the deformed volumes. In the EBSD maps of large indentations, strongly confined deformation patterns were found, while for the shallow indentations the observed patterns are more diffuse. The TEM micrographs and the Selected-Area Electron Diffraction (SAED) support these facts and give insight into the dislocation structure of the deformation zone.

Keywords:

• nanoindentation
• electron backscatter diffraction (EBSD)
• focused ion beam (FIB)
• transmission electron microscopy (TEM)
• selected-area electron diffraction (SAED)

Acknowledgments

The authors thank Professor G. Dehm and J. Thomas for assistance with the TEM investigations. Financial support under the frame of FWF (Fonds zur Förderung der wissenschaftlichen Forschung) through Project P 17375-N07 is gratefully acknowledged.