Coupled microstructural observations and local texture measurements with an automated crystallographic orientation mapping tool attached to a tem

The development of an automated crystal orientation mapping tool attached to a transmission electron microscope is described. The electron beam displacement is controlled by a remote computer while thousands of diffraction patterns are recorded with an external CCD camera and analysed with a dedicated software. The work being mainly concerned with severely deformed metals, spot patterns rather that Kikuchi lines are considered in this approach. The capabilities and the sensitivity of template matching techniques for orientation identification are stressed. To precisely locate the scanned area on TEM pictures, a pseudo-bright field image reconstruction procedure is proposed. A simple procedure to eliminate some orientation ambiguities is described.