SUMMARY
Results are reported concerning the use of an energy dispersive X‐ray detector to carry out the analysis of thin foils in the electron microscope. The combination of a thin specimen and the extreme stability of the energy dispersive X‐ray detector enables the experimental determination of a calibration curve of X‐ray production—detection efficiency vs characteristic X‐ray energy. Quantitative analysis can be carried out using the calibration curve without reference to standards at the time of analysis.
SUMMARY
Techniques are described for identifying and distinguishing between the six varieties of asbestos. When the fibres are large and numerous, as is the case for insulation materials, simple optical or X‐ray methods suffice. For environmental samples one must normally resort to electron microscopic techniques for a positive identification. When asbestiform minerals are to be distinguished from other fibrous silicates it is often necessary to use both electron diffraction and X‐ray spectrometry.
SUMMARY
Results are reported concerning the application of the analytical electron microscope EMMA‐4 to the quantitative analysis of thin foils. A simple procedure by which the observed characteristic X‐ray intensities from a thin foil sample can be converted into chemical weight fractions is described. This technique has been applied to study the partitioning of manganese between the carbide and ferrite phases during the isothermal decomposition of a eutectoid steel. The results show that it is possible to analyse the manganese content of the ferrite and carbide phases independently and the partitioning of manganese to the carbide phase has been followed as a function of time at the isothermal transformation temperature.
The analysis of a calcium‐rich pyroxene which contains calcium‐poor precipitate lamellae is described. The results are consistent with the precipitation of a pigeonite, poor in calcium and rich in iron, from an augite host.
The third example is the ‘in situ’ analysis of nitride precipitates in a stainless steel. The precipitates are known to contain either titanium or chromium, but it is impossible from morphological or diffraction evidence to differentiate between the two types of nitride. Combined electron microscopy and microprobe analysis is shown to be a rapid and positive means of identifying the precipitates.
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