Scanning electron microscopySEM (Scanning Electron Microscopy) with EDS (Energy Dispersive Spectroscopy, elemental analysis) is a very useful and powerful combination for many different applications and for finding solutions to many different types of problems.
How can the instrument be used?
- Imaging at high magnification (with great depth of field) of a surface structure
- Elemental surface analysis, even of small parts or particles
Mapping of a cross-section of a surface coating
Common applications at SP
SEM image of a dental implant
It might be interesting to look at for instance the microstructure of a coating or a surface modified material or to look for contamination, scratches or other defects on a surface. Sometimes there is a need for identifying small particles from the form, structure, etc.
Calculation of porosity, particle density, size distribution, etc.
In combination with image analysis porosity, particle density or size distribution of pores, particles or scratches can be calculated.
Contamination, discoloration, deposits, degree of covering
An EDS analysis shows which elements are present in, for instance, a contamination, discoloration, or a deposit on a surface and also in what concentrations. Mapping can be used to show the lateral distribution of a contamination, how well a thin coating is covering a surface or if there are scratches in a coating.
Particles and dust
The elemental composition of small particles or features on a surface can easily be measured with EDS. For instance it can be of interest to identify particles of unknown origin or to analyze dust particles and compare them with suspected sources.
Thickness measurement of thin layers
Line scan, measured across
a surface layer on a cross-section
Thin layers can be measured using SEM/EDS on a prepared cross-section of a sample. The measurements can also be combined with analysis of the elemental composition of different layers or at different depths in a material.
Failure analysis and corrosion investigations
For many types of failure analysis, SEM with EDS is a very useful combination, since an area can be investigated at high magnification and, if necessary, rapid analysis of interesting areas can be performed at the moment they are discovered. Examples of failure analysis can be to determine the cause of failure of pipes, fittings or other parts, find out why blisters or other defects have occurred in a surface layer or why adhesion is poor between a bulk material and a coating.