title: Cross-sectional measurement of grain boundary segregation using WDS.
abstract: A new method is proposed for the quantification of grain boundary segregation using Wavelength Dispersive Spectroscopy (WDS) in a Scanning Electron Microscope (SEM). Analyses are undertaken on a simple metallographically polished section of material. The method is demonstrated for the model system of sulphur segregation to nickel grain boundaries. Quantification was carried out from sulphur concentration profiles acquired across 11 grain boundaries of a nickel specimen containing 5.4wtppm of sulphur in the bulk and equilibrated at 550°C. The average sulphur grain boundary concentration determined is µ=35.2ngcm-2=6.6×1014atoms cm-2≈0.5 monolayer, which is in good agreement with a previous quantification obtained from SIMS (Secondary Ion Mass Spectrometry) on the same material. However this is lower by a factor of two than the quantification obtained using "surface" techniques on fractured specimens of the same material. With the conditions of analysis used in this study, the limit of detection of the method developed is found to be better than 10% of a sulphur monolayer.
authors: Laboratoire Georges Friedel, CNRS, Ecole des Mines de Saint-Etienne, 158 Cours Fauriel, 42023 Saint-Etienne, France. Electronic address: frederic.christien@emse.fr.
authors: F
authors: F
authors: Christien
authors: Institut des Matériaux Jean Rouxel (IMN), CNRS, Université de Nantes, Rue Christian Pauc, 44306 Nantes, France.
authors: P
authors: P
authors: Risch
keywords: Electron Probe MicroAnalysis (EPMA); Grain boundary segregation; Impurity; Microbeam techniques; Scanning Electron Microscopy (SEM); Wavelength Dispersive X-ray Spectroscopy (WDS)