Innovative Analysis of X-ray Microdiffraction Images on Selected Applications of the Kossel Technique

Abstract

Cryst. Res. Technol. 341999 1 71-88Starting from the origin and the informational content of Kossel interferences excited by electron and synchrotron radiation beams selected examples of microstructural applications, such as the precision determination of lattice constants, the precision determination of crystallographic orientation of single grains, the determination of local stresses/strains and the determination of tetragonal distortions of cubic lattices including the description of a variety of methods for analysis are presented.Ausgehend vom Prinzip der Entstehung und des Informationsgehaltes von elektronenstrahl-bzw. synchrotronstrahlangeregten Kossel-Aufnahmen werden Auswertungsmethoden und Anwendungen im Mikrobereich, wie die Präzisionsgitterkonstantenbestimmung, die Einzelkorn-Orientierungsbestimmung, die Eigenspannungsanalyse sowie die Diagnose von Abweichungen von der kubischen Symmetrie an ausgewählten Beispielen beschrieben.

Effect of the cutting technique on the residual stress distribution of cut edges in FeSi3 transformer sheets

“…In order to determine residual stresses very precisely, it is necessary to detect as many Kossel lines with large Bragg angles as possible. Due to the high diffraction angle, the reflections have a larger distance between the K α1 and K α2 reflections, thus, a high dispersion of the doublets, which results in a high sensitivity to the lattice distortions [16]. In special cases, the accuracy of the Kossel technique for the determination of lattice constants is given as Δa/a =10 -5 to 10 -6 [17,18].…”

A comparison of the KOSSEL and the X‐ray Rotation‐Tilt Technique

“…2a). We also carried out investigations using soft X-rays [12] and hard X-rays [6,7]. Due to the extremely short wavelength of the used synchrotron radiation, the KOSSEL lines appear as a KIKUCHI pattern in the latter case ( Fig.…”

“…Therefore, these techniques can be applied to a wide range of problems in materials diagnostics, e.g. ; high-accuracy determination of crystallographic orientations (for example small grain boundary angles of rotation and tilt angles ≥0.02°), dislocation density determination, determination of decrease in symmetry, high-accuracy determination of lattice constants (∆a/a ≤10 -5 , in special cases 3 * 10 -6 ), precision determination of interplanar spacings (local stresses/strains ∆d/d ≤10 -5 ) and phase identification in micron regions (see also [2,4,5,6,11,12,16]). A modern overview on equipment, detection, and evaluation of these two methods is given in [11,12].…”

“…However, in the intermetallic compound NiAl the Kα radiation of Ni gives rise to record KOSSEL lines with a BRAGG angle of 84° ( Fig. 2a, see also [12]). Due to the high dispersion of the Kα 1 -Kα 2 lines a lattice constant of a=(0.288586±0.000001) nm was measured with the KOSSEL technique for the sample of NiAl [λ NiKα1 =(0.165795±0.000001) nm].…”

Measurements of Residual Stresses in Micron Regions by Using Synchrotron Excited Kossel Diffraction

“…More detailed information about the different ways of analyzing the KOSSEL images according to various application fields (incl. overview) have already been presented [BAUCH et al 1999, ULLRICH et al 1998]. …”