Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-28T01:54:22.674Z Has data issue: false hasContentIssue false
  • English
  • Français

In Situ Study of Deformation Mechanisms in Sputtered Free-Standing Nanocrystalline Nickel Films

Published online by Cambridge University Press:  03 March 2011

R. Mitra ,
A. Chiou  and
J.R. Weertman
R. Mitra
Affiliation:
Department of Materials Science and Engineering, Northwestern University, Evanston, Illinios 60208
A. Chiou
Affiliation:
Department of Materials Science and Engineering, Northwestern University, Evanston, Illinios 60208
J.R. Weertman
Affiliation:
Department of Materials Science and Engineering, Northwestern University, Evanston, Illinios 60208

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Nickel films of 1.5–10-μm thickness, produced by dc magnetron sputtering and with disperse grain size distributions peaking in the 30–60-nm range, were subject to in situ tensile straining in a transmission electron microscope. The deformation was stopped frequently, while keeping the load applied, for transmission electron microscopy observation of the internal structure. Contrast changes occurred in many of the grains between strain increments. Ample evidence was seen of dislocation activity, which appears to be the major mechanism for deformation of the samples. Dislocations were seen in grains as small as 20 nm. Parallel arrays of roughly equally spaced dislocations were observed, spaced about 5–10-nm apart. Intergranular nanovoids were found to form and grow with accompanying strain relief in neighboring grains. The results of the current study are generally consistent with previous in situ investigations and contribute to the understanding of deformation mechanisms in free-standing thin films, which may differ somewhat from those in bulk nanocrystalline materials or in films attached to a substrate.

Keywords

DislocationsNanoscaleTransmission electron microscopy (TEM)
Type
Articles
Information
Journal of Materials Research , Volume 19 , Issue 4 , April 2004 , pp. 1029 - 1037
Copyright
Copyright © Materials Research Society 2004

References

REFERENCES

1Van Swygenhoven, H.: Polycrystalline materials: Grain Boundaries and Dislocations. Science. 296, 66 (2002).CrossRefGoogle ScholarPubMed
2Van Swygenhoven, H. and Derlet, P.M.: Grain boundary sliding in nanocrystalline fcc metals. Phys. Rev. B. 64, 224105 (2001).CrossRefGoogle Scholar
3Van Swygenhoven, H., Derlet, P.M. and Hasnaoui, A.: Atomic mechanism for dislocation emission from nanosized grain boundaries. Phys. Rev. B. 66, 024101 (2002).CrossRefGoogle Scholar
4Derlet, P.M., Van Swygenhoven, H. and Hasnaoui, A.: Atomistic simulation of dislocation emission in nanosized grain boundaries. Philos. Mag. A. 83, 3569 (2003).CrossRefGoogle Scholar
5Hugo, R.C., Kung, H., Weertman, J.R., Mitra, R., Knapp, J.A. and Follstaedt, D.M.: In-situ TEM Tensile Testing of DC Magnetron Sputtered and Pulsed Laser Deposited Ni Thin Films. Acta Mater. 51, 1937 (2003).CrossRefGoogle Scholar
6Kumar, K.S., Suresh, S., Chisholm, M.F., Horton, J.A. and Wang, P.: Deformation of electrodeposited nanocrystalline nickel. Acta Mater. 51, 387 (2003).CrossRefGoogle Scholar
7Youngdahl, C.J., Weertman, J.R., Hugo, R.C. and Kung, H.H.: Deformation behavior in nanocrystalline copper. Scr. Mater. 44, 1478 (2001).CrossRefGoogle Scholar
8Mitra, R., Hoffman, R.A., Madan, A. and Weertman, J.R.: Effect of process variables on the structure, residual stress and hardness of sputtered nanocrystalline nickel films. J. Mater. Res. 16, 1010 (2001).CrossRefGoogle Scholar
9Mitra, R., Ungar, T., Morita, T., Sanders, P.G. and Weertman, J.R. Assessment of grain size distributions in nanocrystalline copper and their effect on mechanical behavior, in Advanced Materials for the 21st Century: The 1999 Julia R. Weertman Symposium , edited by Chung, Y-W., Dunand, D.C., Liaw, P.K., and Olson, G.B. (TMS, Warrendale, PA, 1999), p. 553Google Scholar
10Milligan, W.W., Hackney, S.A., Ke, M. and Aifantis, E.C.: In situ studies of deformation and fracture in nanophase materials. Nanostruct. Mater. 2, 267 (1993).CrossRefGoogle Scholar
11Derlet, P.M. and Van Swygenhoven, H.: The role played by two parallel free surfaces in the deformation mechanism of nanocrystalline metals: A molecular dynamics simulation. Philos. Mag. A. 82, 1 (2002).CrossRefGoogle Scholar
12Hirth, J.P.: The influence of grain boundaries on mechanical properties. Metall. Trans. 3, 3047 (1972).CrossRefGoogle Scholar
13Edington, J.W.: Practical Electron Microscopy in Materials Science (Philips, Eindhoven, 1975), p. 9.Google Scholar