Energy Dispersive X-ray Spectroscopy
EDS Analysis to Determine Elemental Composition
Energy Dispersive X-ray Spectroscopy (EDS), also known as EDS Analysis, is a qualitative and semi-quantitative X-ray microanalytical technique that can provide information about the elemental composition of a sample. The information generated by EDS Analysis can also help in identifying coatings, and in some cases, foreign inorganic substances present in a sample.
EDS Analysis at LTI
The metallurgical engineers at Laboratory Testing Inc. in the Philadelphia, PA (USA) area work with a fully computerized SEM/EDS system that includes a Hitachi S-3400N SEM and an EDAX EDS. The system is powered by TEAM EDS Analysis software for efficiency and to ensure accurate, reproducible results for a wide range of applications.
With the combined Energy Dispersive X-ray Spectroscopy and SEM capabilities, our system can provide:
- Magnification to 300,000x
- Scanning and saving image files
- Identification of major inorganic elements in microscopic samples or small areas of interest on a sample
- Identification of the elements present in contamination particles as small as one micrometer in size
Whether simply collecting a spectrum or performing complex phase analysis, the SEM/EDS provides the examination, results and reporting to meet customer requirements.
- ASTM B748
- MIL Specifications
SEM EDS Analysis provides valuable information for metallurgical testing, elemental composition analysis and failure analysis. Scanning electron microscopy (SEM) is useful for failure analysis since it can reveal where a fracture started, how fast it propagated, and whether the fracture mode was ductile or brittle. Cross sectional measurements of plating thickness (ASTM B748) can also be made with this instrument. The results are in the form of black and white images for our interpretation.
- SEM EDS Analysis – qualitative and semi-quantitative elemental composition
- Identification of coatings, and in some cases, foreign inorganic substances
- Magnification – from 5x to 300,000x
- Sample Size – up to 200 mm (7.87 in.) in diameter and 80 mm (3.14 in.) in height
- Materials Analyzed – solid inorganic materials including metal and polymeric samples
The Test Process
An EDS detector is used to separate the characteristic X-rays of different elements into an energy spectrum. A typical EDS spectrum is charted with X-ray wavelengths or counts vs. intensity or energy (in keV).
During SEM EDS Analysis, an electron beam is scanned across a sample’s surface and the electrons strike and stimulate the sample. Almost instantaneously, as each element returns to its original energy state, it emits X-rays of specific energies and at different wavelengths characteristic of the element. Energy Dispersive X-ray Spectroscopy plots these results with X-ray wavelength on the X-axis and intensity on the Y-axis, and labels each corresponding element. Identification of the elements is done by matching the peak values on the x-axis with known wavelengths for each element to reveal the sample’s elemental composition.