Dresden 2009 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 4: Mechanical Properties II

MM 4.5: Vortrag

Montag, 23. März 2009, 12:45–13:00, IFW B

Research into the parallel determination of Young’s modulus E and Poisson’s ratio ν via normal and lateral nanoindentation experiments — •Andre Clausner and Frank Richter — TU-Chemnitz, Institut für Physik, Germany

In the case of a lot of materials used in various technical applications the assumption of isotropic behaviour can be made. For these materials the most important mechanical properties needed, for example for an FE-simulation of specific geometries, are the Young’s modulus E and the Poisson’s ratio ν. These material constants have to be determined experimentally on a existing structure which is most comparable with the later application. Therefore, as well as for small structures and thin film applications, a very small impact size and depth of the experiment on the structure is favoured. For this purposes instrumented nanoindentation experiments with different indenter shapes are used. In the case of the Young’s modulus we can obtain the value of E via the well know Oliver and Pharr method for instrumented indentation experiments in normal direction. To obtain a second material constant, a second experiment is needed, independent from the normal one. A lateral displacement of a normal loaded spherical indenter in the range of sticking friction is used. For this mechanical loading situation there are some simplified analytical solutions in the elastic theory. Via comparison of the measured lateral data and the analytical model predictions the Poisson’s ratio can be determined. The talk wants to show the possibilities and the recently obtained results of this proceeding to determine ν.