Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-23T00:14:30.626Z Has data issue: false hasContentIssue false

Identifying the limitation of Oliver and Pharr method in characterizing the viscoelastic-plastic materials with respect to indenter geometry

Published online by Cambridge University Press:  01 February 2011

Keerthika Balasundaram
Affiliation:
keerthika.b@mpie.de, Max-Planck-Institut fuer Eisenforschung GmbH, Microstructure Physics and Metal Forming, Duesseldorf, Germany
Yanping Cao
Affiliation:
caoyanping@mail.tsinghua.edu.cn, Institute of Biomechancis and Medical Engineering, Department of Engineering Mechanics, Beijing, China
Dierk Raabe
Affiliation:
d.raabe@mpie.de, Max-Planck-Institut fuer Eisenforschung GmbH, Microstructure Physics and Metal Forming, Duesseldorf, Germany
Get access

Abstract

Nanoindentation tests are widely used in recent years to characterize the mechanical properties of viscoelastic-plastic materials like polymers and biomaterials at the micro or nano-scale using the analysis method proposed by Oliver & Pharr (OP). However, recent studies revealed that the mechanical properties of viscoelastic-plastic (polymeric) materials determined using the OP method does not lead to a correct evaluation of Young's modulus. A systematic experimental study is performed with different indenter geometries like spherical and Berkovich geometries using various polymers in order to identify the limitations of the OP method.

Type
Research Article
Copyright
Copyright © Materials Research Society 2009

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. Kassavetis, S., Mitsakakis, K., Logothetidis, S.: Nanoscale patterning and deformation of soft matter by scanning probe microscopy, Mat. Sci. Eng. C 27, 2007, 1456.Google Scholar
2. Hochstetter, G., Jimenez, A., and Loubet, J. L.: Strain-rate effects on the hardness of glassy polymers in the nanoscale range. Comparison between quasi-static and continuous stiffness measurements. J. Macromol. Sci.-Phys. B. 38, 1999, 681.Google Scholar
3. Oliver, 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, 1992, 1564.Google Scholar
4. Ngan, A.H.W., Tang, B.: Viscoelastic effects during unloading in depth-sensing indentation. J. Mater. Res. 17, 2002, 2604.Google Scholar
5. Cheng, Y. T., Ni, W. Y., and Cheng, C. M.: Determining the instantaneous modulus of viscoelastic solids using instrumented indentation measurements. J. Mater. Res. 20, 2005, 3061.Google Scholar
6. Tranchida, D., Piccarolo, S., Loos, J., Alexeev, A.: Mechanical characterization of polymers on a nanometer scale through nanoindentation. A study on pile-up and viscoelasticity. Macromol. 40, 2007, 1259.Google Scholar
7. Cao, Y.P., Keerthika, B., Raabe, D., On the adhesive contact of a spherical indenter with an elastic halfsapce, in preparation.Google Scholar
8. Lim, Y. Y., Chaudhri, M. M.: Indentation of elastic solids with a Vickers Pyramidal indenter. Mech. Mater. 38, 2006, 1213.Google Scholar
9. Keerthika, B, Cao, Y P, Raabe, D: Mechanical characterization of viscoelastic-plastic soft matter using spherical indentation (in review)Google Scholar
10. Pharr, G.M.: Measurement of mechanical properties by ultra-low load indentation, Materials Science and Engineering A253, 1998, 151.Google Scholar
11. Tervoort, T. A., Govaert, L. E.: Strain-hardening behavior of polycarbonate in the glassy state, J. Rheol. 44(6), 2000, 1263.Google Scholar
12. van Melicka, H.G.H., Bressersa, O.F.J.T., den Toonderb, J.M.J., Govaerta, L.E., Meijer, H.E.H.: A micro-indentation method for probing the craze-initiation stress in glassy polymers, Polymer 44, 2003, 2481.Google Scholar