SEM study of defects in PVD hard coatings using focused ion beam milling

Hard coatings CrN, TiAlN and multilayer CrN/TiAlN were prepared on different substrates (HSS, D2 tool steels, Al-alloy) by thermoionic arc ion plating and by sputtering. The defects incorporated into the coating were studied by four techniques: top view conventional and field-emission SEM, cross-section SEM, AFM and stylus profilometry. As a specifically useful tool to study internal structure of the defect, we applied focused ion beam milling system, which is built in a conventional scanning electron microscope. By ion beam milling we prepared cross-sections through the defects.