Electron Microscopy and X-Ray Diffraction

(Dr. rer. nat. Christoph Somsen, Prof. Dr.-Ing. Gunther Eggeler)

The use of X-ray diffraction and scanning electron microscopy (SEM) allows us to determine a number of important microstructural parameters. With the aid of these two key methods, we can (i) identify crystalline substances and the volume fractions of phases in multiphase materials, (ii) determine textures (e.g. textures associated with solidification processes and thermomechanical treatments and (iii) image, chemically analyse and crystallographically identify small particles (e.g. carbides). SEM also allows to study rupture surfaces to identify the origin of materials failures. The principle of both procedures relies on the interaction of particle waves with crystals. In the SEM section, the origin of contrast, the indexing of electron diffraction patterns and the chemical analysis in the SEM (EDX) is covered. In the section devoted to X-ray analysis, the most important techniques used in materials science are discussed. These include powder diffractrometry, the Laue method, the measurement of internal stresses and texture measurements. Demonstrations using a modern SEM and a modern X-ray diffractometer complement the theory taught in the lectures. The classes are held on in the summer semester on Thursdays from 1.00 pm to 4.00 pm.

Lecture Announcement SS20

ROE&TEM SoSe-20.pdf