CHARACTERISATION OF MATERIALS THROUGH X-RAY MAPPING

Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), wavelength dispersive spectroscopy (WDS) and the combination of these techniques through x-ray mapping (XRM) have become excellent tool for characterising the distribution of elements and phases in materials. Quantitative x-ray mapping (QXRM) enables reliable quantitative results that can be an order of magnitude better than traditional analysis and is also far superior to regions of interest x-ray maps (ROIM) where low levels of an element or elemental overlaps are present. With the development of faster computers, improved electronics, multi-detector systems and more powerful software, XRM can be performed with an EDS spectrum and/or WDS data collected at each pixel point of the SEM image. This allows full characterisation of a material at a latter stage off-line from the instrument. To obtain a better understanding of a material’s chemical and microstructural properties a number of post-processing methods, such as elemental mapping, pseudo colouring, ratio mapping, scatter diagram creation, rotational scatter diagrams and phase mapping should be employed