Thin film analysis of chromium-phosphate conversion coatings on aluminium probed by ToF-SIMS and electron probe x-ray analysis

Time-of-flight SIMS was used to study chromium phosphate conversion layers on Al. During coating formation, fluorine is buried under a layer of CrPxOy as the layer thickens, yielding a duplex layer structure. Electron probe x-ray microanalysis was used to assess the variation in elemental composition of the coating. Preliminary results demonstrate a number of problems related to quantitative analysis of the coatings studied. Copyright @ 2000 John Wiley & Sons, Ltd.