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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:
[email protected], Max-Planck-Institut fuer Eisenforschung GmbH, Microstructure Physics and Metal Forming, Duesseldorf, Germany
Yanping Cao
Affiliation:
[email protected], Institute of Biomechancis and Medical Engineering, Department of Engineering Mechanics, Beijing, China
Dierk Raabe
Affiliation:
[email protected], Max-Planck-Institut fuer Eisenforschung GmbH, Microstructure Physics and Metal Forming, Duesseldorf, Germany
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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

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References

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