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Size dependent hardness of silver single crystals

Published online by Cambridge University Press:  03 March 2011

Qing Ma  and
David R. Clarke
Qing Ma
Affiliation:
Materials Department, College of Engineering, University of California, Santa Barbara. California 93106-5050
David R. Clarke
Affiliation:
Materials Department, College of Engineering, University of California, Santa Barbara. California 93106-5050
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Abstract

The hardness of thick, high-purity, epitaxially grown silver on sodium chloride is found to be dependent on the size of the indentation for sizes below ≃10 μm. The measurement of the size effect has been made in two ways. In one, the hardness has been calculated from the load-displacement curve obtained from an instrumented microhardness testing machine and assuming a geometric self-similarity in the indenter shape. In the other measurement, the hardness was obtained from the load exerted by the microhardness tester divided by the indentation impression area as measured by atomic force microscopy. The observed variation in microhardness with indentation size is consistent with a simplified strain gradient plasticity model in which the densities of the geometrically necessary and statistically stored dislocations are fitting parameters. An equally good fit can also be made with a simple geometric scaling relationship. Transmission electron microscopy observations of a thin (≃50 nm) epitaxial gold film embedded in the silver layers revealed that the deformation was primarily restricted to the sharp edges of the indentation. In addition, deformation twinning within the indentation impression was observed on the {1H} planes.

Type
Articles
Information
Journal of Materials Research , Volume 10 , Issue 4 , April 1995 , pp. 853 - 863
Copyright
Copyright © Materials Research Society 1995

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References

REFERENCES

1Tabor, D., The Hardness of Metals (Clarendon Press, Oxford, 1951).Google Scholar
2Tabor, D., in Microindentation Techniques in Materials Science and Engineering, edited Blau, P. J. and Lawn, B. R., ASTM STP 889 (American Society for Testing and Materials, Philadelphia, PA, 1986), pp. 129–159.Google Scholar
3Samuels, L. E., in Microindentation Techniques in Materials Science and Engineering, edited Blau, P. J. and Lawn, B. R., ASTM STP 889 (American Society for Testing and Materials, Philadelphia, PA, 1986), pp. 5–24.Google Scholar
4Pethica, J. B., Hutchings, R., and Oliver, W. C., Philos. Mag. A48, 593–606 (1983).CrossRefGoogle Scholar
5Gane, N. and Cox, J. M., Philos. Mag. 22, 881 (1970).CrossRefGoogle Scholar
6Doerner, M. F. and Nix, W. D., J. Mater. Res. 1, 601–609 (1986).CrossRefGoogle Scholar
7Chen, C. C. and Hendrickson, A. A., in The Science of Hardness Testing and Its Research Applications, edited by Westbrook, J. H. and Conrad, H. (American Society for Metals, Metals Park, OH, 1973).Google Scholar
8Turley, D. M. and Samuels, L. E., Metallography 14, 275–294 (1981).CrossRefGoogle Scholar
9Pethica, J. B. and Taylor, D., Surf. Sci. 89, 182–190 (1979).CrossRefGoogle Scholar
10Fleck, N. A., Muller, G. M., Ashby, M. F., and Hutchinson, J. W., Acta Metall. Mater. 42, 475–487 (1994).CrossRefGoogle Scholar
11Stelmashenko, N. A., Walls, M. G., Brown, L. M., and Milman, Yu. V., Acta Metall. Mater. 41, 2855–2865 (1993).CrossRefGoogle Scholar
12Nye, J. F., Acta Metall. 1, 153 (1953).CrossRefGoogle Scholar
13Ashby, M. F., Philos. Mag. 21, 399 (1970).CrossRefGoogle Scholar
14Brown, A. R. G. and Ineson, E. J., J. Iron and Steel Institute 169, 376–387 (1951).Google Scholar
15Oliver, W. C. and Pharr, G. M., J. Mater. Res. 7, 1564–1583 (1992).CrossRefGoogle Scholar
16McClintock, F. A. and Argon, A. S., Mechanical Behavior of Materials (Addison-Wesley Publishing Company, Reading, MA, 1966).Google Scholar
17Suzuki, H. and Barrett, C. S., Acta Metall. 6, 156–165 (1958).CrossRefGoogle Scholar