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A mixed metal oxide catalyst coating is subjected to laser irradiation by a Nd:YAG laser operating at 266 nm to induce local changes in surface topography. The coating is exposed to laser interference patterns as well as to direct laser irradiation without interference. Samples are characterized by means of White Light Interferometry and Scanning Electron Microscopy. Irradiation with interference patterns causes the formation of wave‐like surface patterns in micrometer scale whereas direct laser irradiation generates porosity with pore sizes in the range of 100nm. Emissivity‐corrected infrared thermography (ecIRT) is applied to analyze the effect of surface topography changes on the catalytic activity of coatings in parallel. The catalytic combustion of iso‐octane with different contents of oxygen in nitrogen is used as a test reaction for catalytic activity. Local temperature increase on the substrate is chosen as a measure for catalytic activity. For laser interference structured coating, the catalytic activity improves with increase in geometric surface area caused by the wave‐like pattern. For direct laser irradiation, the porosity created by the laser enhances catalytic activity with respect to the unstructured coating.

The characterization of spatial distribution of different phases in materials provides understanding of structural influence on the properties and allows making physically well-grounded correlations. The FIB/SEM nanotomography opens new possibilities for the target microstructure characterization on the scales from 10 nm to 100 μm. It is based on the automatic serial sectioning by the focused ion beam (FIB). Scanning electron microscope in high resolution mode can be used for the imaging of nanostructured materials. Afterwards a detailed three dimensional (3D) image analysis enables the comprehensive quantitative evaluation of local microstructure. The possibilities of these techniques will be presented on the example of silver-composite contact materials which were analyzed using FIB nanotomography before and after exposure to plasma discharge. Significant changes in the spatial distribution of the oxide particles within the switched zone induce among other effects the changes in the local electric and thermal properties. These cause eventually the failure of the contact material. Advanced methods of image analysis allow characterization of inhomogeneous distribution of oxide particles in silver contact materials. Quantitative parameters characterizing the agglomeration of oxide inclusions and accumulation of pores can be derived from the results of distance transformations and morphological operations. The additional consideration of the connectivity allows the quantification of homogeneous and inhomogeneous states with high sensitivity and confidence level. Local thermal and electrical properties were estimated using simulation software on the real tomographic data. The combination of FIB microstructure tomography with modern 3D analysis and simulation techniques provides new prospects for targeted characterization and thus understanding of the microstructure formation and local effect associated with e.g. electro-erosion phenomena [1], [2]. First correlations between 3D microstructure parameters and resulting properties will be discussed.

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The understanding of the degradation mechanisms of contact materials is a key issue for the development of new materials with enhanced durability. This can be achieved through the investigation of the microstructure modification caused by electrical arcs on the surface of contacts. In this work, the erosion behaviour of pure silver and silver based composites as well as the characterization in two or three dimensions is presented. Single breaking operations were performed with direct current. Using white light interferometry, the size of the craters on the surface as well as the volume of eroded material has been measured. By means of dual beam techniques, the microstructural modifications in the crater have been investigated and reconstructed in three dimensions.