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Correction factor for contact area in nanoindentation measurements

Published online by Cambridge University Press:  01 March 2005

Michel Troyon*
Affiliation:
Laboratoire de Microscopies et d'Etude de Nanostructures, EA 3799, Université de Reims, 51685 Reims Cedex 2, France
Liye Huang
Affiliation:
Laboratoire de Microscopies et d'Etude de Nanostructures, EA 3799, Université de Reims, 51685 Reims Cedex 2, France
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

In the relationship between unloading contact stiffness, elastic modulus, and contact area, which is the fundamental basic equation for nanoindentation analysis, a multiplicative correction factor is generally needed. Sometimes this correction factor is called γ to take into account the elastic radial inward displacements, and sometimes it is called β to correct for the fact that the indenter shape is not a perfect cone. In reality, these two effects simultaneously coexist and thus it is proposed that this correction factor is α = βγ. From nanoindentation data measured on three materials of different elastic moduli with a sharp Berkovich indenter and a worn one, the tip of which was blunt, it is demonstrated that the correction factor α does not have a constant value for a given material and indenter type but depends on the indenter tip rounding and also on the deformation of the indenter during indentation. It seems that α increases with the tip radius and also with the elastic modulus of the measured materials.

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Articles
Copyright
Copyright © Materials Research Society 2005

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References

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