NEW METHOD OF BURGERS VECTOR IDENTIFICATION FROM ELECTRON-MICROSCOPE IMAGES

A new method for the identification of the dislocation Burgers vector is proposed. The method makes use of characteristics of dislocation images in electron micrographs, especially their asymmetry. The asymmetry is related to the sign of g · b or g. (b × u), where g, b and u are the reflection vector, the Burgers vector and the dislocation-line vector, respectively. Inspection of the asymmetry, therefore, gives information concerning the oriontation of the vector b if the vector g is known. From knowledge of the signs for several different reflections, the possible orientation of the Burgers vector can he determined to lie within a small solid angle. Then the Burgers vector can be chosen uniquely from among erystallographically allowable vectors. The method is illustrated by a real example of a dislocation in Fe–3 M.25 wt.% Si alloy, in which only two photographs taken in different reflections were enough to identify the Burgers vector. © 1979 Taylor & Francis Group, LLC.