Hostname: page-component-848d4c4894-mwx4w Total loading time: 0 Render date: 2024-07-04T22:42:07.692Z Has data issue: false hasContentIssue false

Initial Contact Behavior of Nanograined Ni-25at.%Al Film During Nanoindentation

Published online by Cambridge University Press:  01 February 2011

Han. Li
Affiliation:
Department of Mechanical Engineering, the University of Hong Kong Pokfulam Road, Hong Kong, P. R. China
Alfonso H. W. Ngan
Affiliation:
Department of Mechanical Engineering, the University of Hong Kong Pokfulam Road, Hong Kong, P. R. China
Get access

Abstract

Cyclic indentation was performed on standard fused quartz, single crystal Ni3Al (111) and nanocrystalline Ni-25at. %Al alloy thin film with average grain size of a few nanometers. For the thin film sample, it is found the scattering of the effective Young's modulus at small depths goes far beyond the expectation from effects due to surface roughness alone. Three representative deformation mechanisms during initial contact stage were identified to be responsible for the scattering with the assistance of immediate pre and post indentation atomic force microscopy imaging. Furthermore, repeated loading was found to stiffen the thin film sample, but not the bulk ones.

Type
Research Article
Copyright
Copyright © Materials Research Society 2005

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Oliver, W.C. and Pharr, G.M., J. Mater. Res., 7(6) (1992).Google Scholar
2. Mayo, M.J., Siegel, R.W., Liao, Y.X., and Nix, W.D., J. Mater. Res., 7(4) (1992).Google Scholar
3. Chen, J., Wang, W., Qian, L.H., and Lu, K., Scripta Materialia, 49 (2003).Google Scholar
4. Ng, H.P. and Ngan, A.H.W., Journal of Applied Physics, 88(5) (2000).Google Scholar
5. Anand, T.J.S., Ng, H.P., Ngan, A.H.W., and Meng, X.K., Thin Solid Films, 441(1–2) (2003).Google Scholar
6. Ngan, A.H.W., Pethica, J.B., and Ng, H.P., Journal of Materials Research, 18(2) (2003).Google Scholar
7. Ng, H.P. and Ngan, A.H.W., Journal of Materials Research, 17(8) (2002).Google Scholar
8. Johnson, K.L., Contact mechanics, (Cambridge University Press, Cambridge, 1985), p.92.Google Scholar
9. Wang, W. and Lu, K., Journal of Materials Research, 17(9) (2002).Google Scholar
10. Li, H. and Ngan, A.H.W., Scripta Materialia, submitted (2004).Google Scholar
11. Jin, M., Minor, A.M., Stach, E.A., and Morris, J.W.J., Acta Materialia, 52 (2004).Google Scholar