Lokale Verformungsanalyse an einkristallinen Cu- und Au-Mikrozugproben mit Hilfe von Bildkorrelationsverfahren und AFM-Messungen

Translated title of the contribution: Local deformation analysis of single-crystalline Cu- and Au-micro-tensile samples using image correlation methods and AFM-measurements

Ruth Konetschnik

Research output: ThesisDiploma Thesis

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Abstract

Due to the ongoing miniaturization of devices also their metallic components become smaller and smaller. Therefore it is highly important to understand the mechanical properties and the deformation behaviour of metals in small dimensions (in the order of few microns and less). In small volumes the deformation is often concentrated on only a few slip-steps. This causes a much higher local than global strain. So it is required to map and to quantify local strains to achieve a better understanding of the underlying processes. One option to map local strains is provided by image correlation methods. Scanning electron microscope images (SEM-images) are taken at different amounts of plastic strains and are then compared by a matching algorithm. The obtained data is used to plot strain maps which show the local surface strains. Another option is to carry out AFM-measurements (atomic force microscope) to measure the height of the slip steps (which is also a measure for the local strain). As AFM-measurements are suited best for small deformations and the results of image correlation methods provide good results at higher plastic strains, a combination of both methods leads to the best achievable survey of the whole strain regime. The samples tested for this diploma thesis were manufactured with the use of a focused ion beam workstation (FIB) out of copper and gold single crystals in well-defined orientations. Afterwards they were mechanically tested in-situ in the SEM. It can be shown that it is possible to prepare micro-tensile samples in such a way that image correlation methods provide qualitative meaningful data. But at this point it is not possible to quantify the deformation process. This also holds true for the AFM-measurements. As the measurements have to be conducted outside the SEM it is very time-consuming to image more than one deformation step to get a better survey of the whole deformation process. Therefore both techniques will have to be optimized which will be done in future theses. The development of an in-situ AFM, for example, which is currently one project at the institute, will enable us to gain more detailed information about the local deformation behaviour of metals in the near future.
Translated title of the contributionLocal deformation analysis of single-crystalline Cu- and Au-micro-tensile samples using image correlation methods and AFM-measurements
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
  • Motz, Christian, Supervisor (internal)
Award date14 Dec 2012
Publication statusPublished - 2012

Bibliographical note

embargoed until null

Keywords

  • micromechanics
  • tensile test
  • image correlation methods
  • atomic force microscopy (AFM)
  • dislocations
  • plastic deformation

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