Journal article
Deformation micromechanisms of ZnO single crystals as determined from spherical nanoindentation stress–strain curves
Journal of materials research, v 22(9), pp 2470-2477
01 Sep 2007
Abstract
In this work, instrumented nanoindentation experiments with two spherical tips with radii of 13.5 and 1 μm were used to explore the deformation behavior of ZnO single crystals with two orientations, C (basal) and A (prism). By converting the nanoindentation load–displacement data to stress–strain curves, we show that the main reason the hardening rates are higher for the C plane than they are for the A plane is the activation of dislocations—with widely different flow stresses—on different sets of slip planes. For the former, glide occurs on basal planes as well as pyramidal planes; for the latter, glide occurs predominantly on basal planes. The C plane is roughly twice as hard as the A plane, probably due to the orientation of basal planes with respect to the indentation axis. A Weibull statistical analysis of the pop-in stresses indicates that the inherent defect concentration at or near the surface is the main factor for the initiation of plastic deformation. The strain energy released when the pop-ins occur determines their extent. The elastic moduli values, determined by Berkovich nanoindentation, are 135 ± 3 GPa and 144 ± 4 GPa for the C and A planes, respectively. In the C orientation repeated indentations to the same stress result in fully reversible hysteretic loops that are attributed to the formation of incipient kink bands.
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Details
- Title
- Deformation micromechanisms of ZnO single crystals as determined from spherical nanoindentation stress–strain curves
- Creators
- Sandip Basu - Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104Michel W. Barsoum - Drexel University, Materials Science and Engineering
- Publication Details
- Journal of materials research, v 22(9), pp 2470-2477
- Publisher
- Cambridge University Press
- Number of pages
- 8
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Materials Science and Engineering; School of Engineering
- Web of Science ID
- WOS:000249170700017
- Scopus ID
- 2-s2.0-34748866601
- Other Identifier
- 991014632202604721
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Web of Science research areas
- Materials Science, Multidisciplinary