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Bilinear Behavior in the Indentation Size Effect: A Consequence of Strain Gradient Plasticity

Published online by Cambridge University Press:  11 February 2011

A. A. Elmustafa ,
J. Lou ,
O. Adewoye ,
W. O. Soboyejo  and
D. S. Stone
A. A. Elmustafa
Affiliation:
NASA Langley Research Center-ConITS, Hampton, VA, U.S.A
J. Lou
Affiliation:
Department of Mechanical and Aerospace Engineering and Princeton Materials Institute, Princeton, NJ, U.S.A
O. Adewoye
Affiliation:
Department of Mechanical and Aerospace Engineering and Princeton Materials Institute, Princeton, NJ, U.S.A
W. O. Soboyejo
Affiliation:
Department of Mechanical and Aerospace Engineering and Princeton Materials Institute, Princeton, NJ, U.S.A
D. S. Stone
Affiliation:
Materials Science & Engineering, University of Wisconsin-Madison, WI, U.S.A
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Abstract

This paper examines the effects of stacking fault energy on the micro- and nano-indentation behavior of face-centered-cubic thin films. These include: LIGA nickel MEMS structures, alpha brass, copper and high purity aluminum. The measured hardness are then fitted to a strain gradient plasticity model based on the Taylor dislocation hardening model. Hardness is shown to exhibit a size dependence with different characteristic slopes in the micron and nano-scale regimes. Deep indents are shown to exhibit classical linear behavior. However, shallow indents exhibit an abrupt decrease in slope (almost by a factor of 10), giving rise to a bi-linear behavior. Furthermore, as the gradients become less sharp, the trends in the nano-hardness data become similar to those of the microhardness data predicted by the strain gradient plasticity model. Finally, the effects of stacking fault energy are then discussed within the context of cross-slip and hardening associated with Shockly partials.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 750: Symposium Y – Surface Engineering 2002–Synthesis, Characterization and Applications , 2002 , Y1.7
Copyright
Copyright © Materials Research Society 2003

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References

REFERENCES

1. Nix, W.D., Gao, H., J. Mech. Phys. Solids, 46, 411 (1998).Google Scholar
2. Stelmashenko, N.A., Walls, M.G., Brown, L.M. and Milman, Y.V., Mechanical Properties and Deformation Behavior of Materials Having Ultra-Fine Microstructures, eds. Nastasi, M., Parkin, D.M. and Gleiter, H., NATO ASI Series E 233, 602 (1993).Google Scholar
3. Ma, Q., and Clarke, D.R., J. Mater. Res. 10, 853 (1995).Google Scholar
4. Poole, W.J., Ashby, M.F. and Fleck, N.A., Scripta Materialia, Vol. 34, 559 (1996).Google Scholar
5. Lou, J., Shrotriya, P., Buchheit, T.E., Yang, D. and Soboyejo, W.O., Journal of Materials Research, Accepted.Google Scholar
6. Elmustafa, A.A., and Stone, D.S., J. Mech. Phys. Solids, 51, 357 (2003).Google Scholar
7. Begley, M.R. and Hutchinson, J.W., J. Mech. Phys. Solids, Vol. 46, 2049 (1998).Google Scholar
8. De Guzman, M.S., Neubauer, G., Flinn, P. and Nix, W.D., Materials Research Symposium Proceedings, Vol. 308, 613 (1993).Google Scholar
9. Christensen, T., Buchheit, T., Schmale, D.T., and Bourcier, R.J., Microelectromechanical Structures for Materials Research, MRS, eds. Brown, S. et al., 185 (1999).Google Scholar
10. Buchheit, T.E., LaVan, D.A., Michael, J. R., Chrinstenson, T.R. and Leith, S. D., Metallurgical and Materials Transactions, 33, 539 (2002).Google Scholar
11. Stone, D.S. and Yoder, K.B., MRS., 308, eds. Townsend, P. H., Weihs, T., Sanchez, J. E. Jr, and Borgensen, P., Pittsburgh, PA, 121 (1993).Google Scholar
12. Stone, D.S., Yoder, K.B., and Sproul, W.D., J. Vac. Sci. Technol., A, 9, 2543 (1991).Google Scholar
13. Joslin, D.L., Oliver, W.C., J. Mater. Res., 5, 123 (1990).Google Scholar
14. Oliver, W.C. and Pharr, G.M., J. of Mater. Res., Vol. 7, 1564 (1992).Google Scholar
15. Fleck, N.A., Muller, G.M., Ashby, M.F., and Hutchinson, J.W., Acta Metall. Mater. 42, 475 (1994).Google Scholar
16. Fleck, N.A., and Hutchinson, J.W., J. Mech. Phys. Solids, 41, 1825 (1993).Google Scholar
17. Lim, Y.Y., and Chaudhri, M.M., Phil. Mag. A. 79, 2979 (1999).Google Scholar