Recent applications of SEM and AFM for assessing topography of metal and related coatings - a review

Recent literature describing the use of scanning electron microscopy (SEM) and atomic force microscopy (AFM) in the investigation of morphology and topography of metal surface coatings has been reviewed. SEM has been shown to give valuable data on many properties such as film uniformity, thickness and cracking, wear patterns and debris, and bond failures. In addition, much information is made possible on coating phase structure, grain size and boundaries, uniformity and heterogeneity, growth mechanisms and porosity. Combined with energy dispersive X-ray analysis and chemical mapping techniques, SEM can be especially powerful. The newer technique of AFM has some advantages over SEM; however, studies tend to focus on imaging nanostructures and quantitative determination of deposit surface roughness. Advances in the application of the technique are expected to further its use, for example, in the measurement of friction, adhesion and elasticity.