HR: 09:30h
AN: MR21A-07    [Abstracts]
TI: Orientation and misorientation analysis on public domain software
AU: * Heilbronner, R
EM: renee.heilbronner@unibas.ch
AF: Basel University, Geological Institute, Bernoullistr. 32, Basel, CH-4056, Switzerland
AU: Barrett, S
EM: S.D.Barrett@liverpool.ac.uk
AF: University of Liverpool, Department of Physics, Liverpool, L69 7ZE, United Kingdom
AU: Herwegh, M
EM: marco.herwegh@geo.unibe.ch
AF: University of Bern, Institute of Geological Sciences, Baltzerstrasse 1-3, Bern, CH-3012, Switzerland
AB: One of the great advances in microstructure analysis was the introduction of electron back scatter diffraction (EBSD). Based on the scanning electron microscope it is essentially an imaging tool, capable of analysing the complete crystallographic orientation (three Euler angles) at each point (pixel) of the sample surface. An alternative is optical orientation imaging which can be achieved with computer-integrated polarization microscopy (CIP). This method is capable of analysing the orientation of the optical axis (azimuth and inclination) of uniaxial minerals at each pixel of the thin section. Both methods have their merits: EBSD can derive the complete texture of all minerals, CIP is fast, has a high spatial resolution and is public domain. We have now merged CIP with Image SXM (a public domain software developed from NIH Image, www.liv.ac.uk/~sdb/ImageSXM/). A special version of this program calculates azimuth and inclination of c-axes from a set of optical micrographs (like the CIP method) and stores them in two image planes. From these, different types of orientation and misorientation images are calculated and displayed. Different types of masks can be used to select areas of analysis. Images of orientation gradients, orientation profiles and histograms can be displayed, c-axis polefigures can be calculated, for the entire image or for selected areas only. The standard image analysis tools of Image SXM can be applied in order to derive and analyze the microstructure by grain boundary detection, grain size and grain shape determination, ACF analysis, etc.. Three additional image planes can be used for the Euler angles from EBSD analysis. These can be visualized and analyzed by first converting to CIP type orientation images and then applying the same analysis methods as described above. Alternatively, direct analysis and visualization of the three Euler planes is possible too. In this form the program is a valuable extension of the EBSD imaging and analysis software provided by the producers of EBSD equipment, allowing users to study their results off-line. In this presentation we demonstrate the use of such a combined texture analysis. We will present diffrent types of misorientations measurements and their relevance for the interpretation of deformation mechanisms.
DE: 8030 Microstructures
SC: Mineral and Rock Physics [MR]
MN: 2007 Fall Meeting