Automated Determination of LatticeOrientation From ElectronBackscattered KikuchiDiffraction Patterns

Abstract

As described in a previous paper (Wright and Adams, 1990), with the advent of new techniques it has become practical to consider using single orientation measurements for texture investigations. Advantages of using single orientations measurements over the traditional bulk measurement using pole figures are: direct access to odd‐ l terms in the series expansion of the Orientation Distribution Function (ODF) (Bunge, 1982) and the capability to measure local textures and to obtain spatial orientation correlation information. The primary obstacle to the use of single orientation measurements is the large investment of direct operator time required to obtain a statistically reliable data set. This study examines a technique that has been developed to automate the orientation identification process. The technique essentially compares an electron backscattered Kikuchi diffraction (BKD) pattern with a set of idealized patterns and finds the best match. The set of idealized patterns is created from a set of orientations which represent a tessellation of the asymmetric region of Euler space. The technique shows promising preliminary results, BKD patterns for silicon and stainless steel were correctly identified by the computer.