The precise characterization of the local microstructure
situation is a precondition to investigate and to understand the degradation
phenomena occurring in electrical contact materials, because the
microstructure is the unique and authentic monitor of the whole materials
experience. However, it could not be fully exploited so far due to the lack
of adequate characterization techniques. The recently developed
FIB-nanotomography may solve this problem. It is based on the automatic
serial sectioning by a focused ion beam (FIB) of the volume of interest at
the nanoscale and offers an optimum resolution in x-y-z directions. For
imaging all well established contrast information of the scanning electron
microscopy (chemistry, phase composition, grain structure, texture, stress
and strain) is available. After imaging, a detailed 3D image analysis
enables the comprehensive quantitative evaluation of local microstructure
degradation effects. This work gives an overview of these new possibilities
using the example of a Ag/SnO2 contact material in its initial state
and after switch operations.