Energy-dispersive X-ray spectroscopy in the SEM: which elements are present, and where. Typical questions - What is this particle or residue made of? - Is the coating composition uniform across the part? - Where are the elements distributed in a cross-section? Good to know - EDS is semi-quantitative. It does not certify an alloy grade. - Light elements are difficult, and carbon in particular is unreliable because of surface contamination. - The signal comes from up to a few micrometers below the surface, depending on beam voltage and material, so thin layers are averaged with what is under them.
