Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-28T16:03:11.688Z Has data issue: false hasContentIssue false
  • English
  • Français

On the indentation contact area of a creeping solid during constant-strain-rate loading by a sharp indenter

Published online by Cambridge University Press:  03 March 2011

Naoki Fujisawa  and
Michael V. Swain
Naoki Fujisawa*
Affiliation:
School of Aerospace, Mechanical & Mechatronic Engineering, University of Sydney, Sydney, NSW 2006, Australia
Michael V. Swain
Affiliation:
Biomaterials Unit, Department of Oral Sciences, School of Dentistry, University of Otago, Dunedin, New Zealand; Biomaterials Science Research Unit, Faculty of Dentistry, University of Sydney, United Dental Hospital, Surry Hills, NSW 2010, Australia; and School of Aerospace, Mechanical & Mechatronic Engineering, University of Sydney, Sydney, NSW 2006, Australia
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Poly(methyl methacrylate) was contacted by a Berkovich indenter at a range of constant loading strain rates. This particular loading scheme was used to maintain the strain-rate-dependent elastic modulus and indentation hardness of the creeping solid constant throughout loading. A loading curve analysis method identical to that of Malzbender and de With but based on the elastic-perfectly plastic contact model of Hochstetter et al. [Tribol. Int.36, 973–985, 2003] was used to process the load-displacement curves. Using the analysis method together with the strain-rate-dependent elastic modulus of the creeping solid known a priori, the strain-rate-dependent hardness could then be predicted. The predicted hardness versus strain-rate relationship was compared with that evaluated from the observed topographic images of the residual impressions due to heavier indentations at three constant loading strain rates. Based on this comparison, the elastic-perfectly plastic contact model was shown to be applicable to the creeping solid only when deformation takes place at a quasi-static strain rate.

Keywords

Elastic propertiesHardnessPolymer
Type
Articles
Information
Journal of Materials Research , Volume 22 , Issue 4 , April 2007 , pp. 893 - 899
Copyright
Copyright © Materials Research Society 2007

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

1Oliver, W.C. and Pharr, G.M.: An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments. J. Mater. Res. 7, 1564 (1992).Google Scholar
2Oliver, W.C. and Pharr, G.M.: Measurement of hardness and elastic modulus by instrumented indentation: Advances in understanding and refinements to methodology. J. Mater. Res. 19, 3 (2004).CrossRefGoogle Scholar
3Bec, S., Tonck, A., Georges, J-M., Georges, E., and Loubet, J.L.: Improvements in the indentation method with a surface force apparatus. Philos. Mag. A 74, 1061 (1996).Google Scholar
4Sneddon, I.N.: The relation between load and penetration in the axisymmetric Boussinesq problem for a punch of arbitrary profile. Int. J. Eng. Sci. 3, 47 (1965).Google Scholar
5Hochstetter, G., Jimenez, A., Cano, J.P., and Felder, E.: An attempt to determine the true stress-strain curves of amorphous polymers by nanoindentation. Tribol. Int. 36, 973 (2003).Google Scholar
6Malzbender, J. and de With, G.: The use of the loading curve to assess soft coatings. Surf. Coat. Technol. 127, 266 (2000).Google Scholar
7Tabor, D.: The hardness of solids. Rev. Phys. Technol. 1, 145 (1970).Google Scholar
8Fujisawa, N. and Swain, M.V.: Effect of unloading strain rate on the elastic modulus of a viscoelastic solid determined by nanoindentation. J. Mater. Res. 21, 708 (2006).CrossRefGoogle Scholar
9Mayo, M.J. and Nix, W.D.: A micro-indentation study of superplasticity in Pb, Sn, and Sn–38 wt% Pb. Acta Metall. 36, 2183 (1988).CrossRefGoogle Scholar
10Lucas, B.N., Oliver, W.C., Pharr, G.M., and Loubet, J.L.: Time dependent deformation during indentation testing, in Thin Films: Stresses and Mechanical Properties VI, edited by Gerberich, W.M., Gao, H., Sundgren, J-E. and Baker, S.P. (Mater. Res. Soc. Symp. 436, Pittsburgh, PA, 1997), pp. 233–238.Google Scholar
11Cheng, Y-T. and Cheng, C-M.: Scaling, dimensional analysis, and indentation measurements. Mater. Sci. Eng. Rep. Rev. J. R44, 91 (2004).Google Scholar
12Berthoud, P., G’Sell, C., and Hiver, J.M.: Elastic-plastic indentation creep of glassy poly(methyl methacrylate) and polystyrene: characterization using uniaxial compression and indentation tests. J. Phys. D: Appl. Phys. 32, 2923 (1999).Google Scholar
13Feng, G. and Ngan, A.H.W.: Effects of creep and thermal drift on modulus measurement using depth-sensing indentation. J. Mater. Res. 17, 660 (2002).Google Scholar
14Tang, B. and Ngan, A.H.W.: Accurate measurement of tip-sample contact size during nanoindentation of viscoelastic materials. J. Mater. Res. 18, 1141 (2003).Google Scholar