Automated EBSP studies of deformation microstructures

Abstract

Measurements of the crystallographic orientation within selected local areas of the microstructure is important to achieve further understanding of the development of deformation microstructures and texture; for example for studies of grain subdivision and texture formation. Different techniques may be applied. The most clear and precise results relating directly specific microstructural features to given orientations (or misorientations) are obtained by TEM methods. However, better statistical data may be obtained by the electron back scattering pattern (EBSP) technique in the SEM. The present paper concentrates on the EBSP technique and result obtained thereby.Characterization of the distribution of orientations in the deformation microstructures by EBSP generally requires measurements of hundreds or more orientations. Automatic techniques are therefore very adequate. By using a modified Hough transform routine, lines in an EBSP are easily and rapidly identified. Figure 1 shows an example of computer identified lines in an EBSP of aluminum. Based on this data the crystallographic orientation is calculated by standard routines.