Einfluss der Indentergeometrie auf die Resultate von Indentationsmessungen

Research output: ThesisDiploma Thesis

Organisational units

Abstract

Currently the characterisation and understanding of material behaviour in sub micron dimension is one of the primary goals of materials science. For investigating smaller dimensions, new or at least adapted methods are needed. One of these techniques is nanoindentation which is an adaptive design of conventional hardness testing. By using this technique it's possible to get hardness and Youngs modulus by one test. Another advantage is that only little specimen preparation is required. Nanoindentation is very well developed concerning isotropic materials like polycrystals. By using this method for anisotropic materials (single crystals, cellulose fibres,...) the experimental results are different compared to other methods and physical models. Even though there are methods to recalculate the indentation modulus to a Youngs modulus with respect to different orientations it keeps a dream to measure the Youngs modulus of the indentation direction. Most of the commercial indenters are sharp or at least spherical, which should cause simultaneous response of different crystal directions during indentation. The idea of this work was to use a flatpunch indenter and to discover, if it is possible to measure the correct Youngs modulus of an isotropic material. Single crystals of copper with different orientations and cellulose fibres were used. All samples were tested by using a flatpunch, Berkovich, cone and cube corner to understand the influence of different tips on the result.

Details

Translated title of the contributionInfluence of the indenter shape on the results of indentation measurements
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
Award date19 Dec 2008
Publication statusPublished - 2008