Papers by Keyword: Backscatter Kikuchi Diffraction (BKD)

Abstract: A high speed in acquisition of backscatter Kikuchi patterns (BKP) and solving the stored raw patterns offline has many advantages over online EBSD. No compromise is made between speed and reliability. Automated backscatter Kikuchi diffraction in the scanning electron microscope (SEM) is about to become a tool for process and quality control. Mandatory requirements for these applications are measures to enable re-examination of the results at any time and a high speed. Therefore, fast acquisition of pattern sequences and off¬line indexing will soon become standard. Online pattern solving is optional, but at the disadvantage of reduced speed and reliability.

Abstract: In this work the textures of MgAl9Zn1, MgAl6Zn1, MgAl3Zn1 and MgAl2Mn alloys have been studied, using individual grain orientation measurement (“ACOM”) in the SEM. Hot extruded billets, unidirectional, reverse and cross-rolled sheet metals as well as laser welding seams have been investigated. In the shaft of a partial extrudate through a circular die orifice, a <0001> ring fiber texture has formed which continuously changes into a spiral fiber texture in the bottom neck. The unidirectional and the reverse hot rolled MgAl2Mn specimens show an R type <0001> texture with a small asymmetrical split whereby the basal poles are tilted by about ±12° from the sheet normal direction to the rolling direction. In the hot cross rolled specimens, the basal poles are slightly spread both in the first and second rolling directions. Texture in the laser welding seams is weak and distinctly different from that of the sheet material. There is almost no heat affected zone at the margins of the welding seams.