Electron Probe Microanalysis - EPMA
The electron microprobe is an electron microbeam instrument like an SEM, but different in that it is highly specialised to provide superior accuracy in elemental analysis using the X-ray emissions induced by an electron beam.
Our microprobe utilises seven wavelength dispersive spectrometers (WDS) for determining chemical information on a micron-by-micron scale. Each WDS can be tuned to a specific element to provide fully quantitative analysis on metallographically prepared specimens.
The X-ray resolution provided by the microprobe using WDS is about an order of magnitude better than EDS, which eliminates many of the pathological spectrum peak overlaps observed using EDS. In addition, detection limits are about one hundred times better than EDS and elements as light as Boron can be quantitatively measured.
Microprobe features
A few of the notable features of our system are:
- it is one of the world's fastest electron microprobes, with seven wavelength dispersive X-ray spectrometers (WDS) and a silicon drift detector energy dispersive X-ray spectrometer (SDD-EDS)
- it has the highest take-off angle of any commercial electron microprobe for the greatest accuracy and sensitivity
- it produces ultra-fast colour X-ray element maps capable of incorporating signals from both EDS and WDS detectors
- it has the capability to discern most of the periodic table of elements, from boron to uranium on a microscopic scale
Microprobe experience
Our microprobe analysis has been used to support research, development, manufacturing, maintenance, and repair across several industries.
Examples of the types of analyses we have conducted include:
- elemental diffusion profiles across weld and braze joints. Also, across glass defects.
- phase characterisations to identify stoichiometry of various carbides, borides, and intermetallics
- corrosion product identification
- identification of residue left by foreign and domestic object damage in support of failure analyses
- material identification of unknown contaminants
- x-ray element mapping to identify spatial variation in chemistry
Example analysis
Solving Problems by Materials Analysis with an Electron Microprobe