High‐Resolution Imaging of Texture and Microstructure by the Moving Detector Method

Abstract

In order to describe texture and microstructure of a polycrystalline material completely, crystal orientation g ¼ {' 1 È ' 2 } must be known in all points x ¼ {x 1 x 2 x 3 } of the material. This can be achieved by locationresolved diffraction of high-energy, i.e. short-wave, X-rays from synchrotron sources. Highest resolution in the orientation-as well as the location-coordinates can be achieved by three variants of a detector ''sweeping'' technique in which an area detector is continuously moved during exposure. This technique results in two-dimensionally continuous images which are sections and projections of the six-dimensional ''orientation-location'' space. Further evaluation of these images depends on whether individual grains are resolved in them or not. Because of the high penetration depth of high-energy synchrotron radiation in matter, this technique is also, and particularly, suitable for the investigation of the interior of big samples.

In-situmeasurement of annealing kinetics of individual bulk grains in nanostructured aluminium

“…This requires high penetration power as well as fast measurements. High energy (50-100 keV) X-rays give the necessary penetration power (mm -cm in typical materials) and several experimental approaches have been developed for full 3D mapping of the microstructure [17][18][19][20]. However these methods rely on scanning principles to obtain the full 3D information, which typically makes them too slow for in-situ kinetics investigation.…”

Measurement of High-Resolution Recrystallization Textures in Nickel Sheets Using High-Energy Synchrotron Radiation

“…During exposure the detector is being shifted continuously while, at the same time, the sample is being rotated or translated, continuously, too. This technique allows to measure different types of two-dimensional images which are sections and projections of the sixdimensional orientation-location space [5,6,7]. The different methods were used to study orientation and local distributions of crystallites in recrystallized Ni sheets and hot rolled and subsequently annealed Al-alloy samples [8].…”

“…This can be done by location-resolved diffraction of highenergy synchrotron radiation [4,5,6]. In order to fully exploit the high resolving power of this radiation, the conventional step-scan technique had to be replaced by a continuous "sweeping" technique with a moving detector [5,6,7]. For this purpose either a diffraction angle slit or a diffraction plane slit was introduced additionally between sample and detector in the diffractometer at the high-energy beam-line BW5 at HASYLAB [6,7].…”

“…During exposure the detector is being shifted continuously while, at the same time, the sample is being rotated or translated, continuously, too. This technique allows to measure different types of two-dimensional images which are sections and projections of the sixdimensional orientation-location space [5,6,7]. …”

“…In order to fully exploit the high resolving power of this radiation, the conventional step-scan technique had to be replaced by a continuous "sweeping" technique with a moving detector [5,6,7]. For this purpose either a diffraction angle slit or a diffraction plane slit was introduced additionally between sample and detector in the diffractometer at the high-energy beam-line BW5 at HASYLAB [6,7]. During exposure the detector is being shifted continuously while, at the same time, the sample is being rotated or translated, continuously, too.…”