Published online by Cambridge University Press: 22 December 2009
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.