Development and optimisation of focused ion beam/scanning electron microscopy as a technique to investigate cross-sections of organic coatings

Focused ion beam/scanning electron microscope (FIB/SEM) was found to be a useful technique to study the cross-sections of pre-painted metal. Information from secondary and backscatter electrons images can reveal the quality of the coating (for example adhesion to substrate, pigment dispersion, interfacial properties etc.) and also the thickness of the coating causing less damage to the sample compared to other mechanical sectioning techniques. Additionally it offers the ability to look at specific areas of interest such as defects, contamination and corroded areas. Energy dispersive X-ray spectroscopy (EDS) analysis allows mapping of the elements which are shown distributed in the coating and also the quantification of those elements. The results obtained from EDS analysis were representative of the components that were formulated into the pre-painted metal product.