Observation of dislocation dynamics in the electron microscope

Deformation experiments performed in situ in the transmission electron micr oscope have led to an increased understanding of dislocation dynamics. To i llustrate the capability of this technique two examples will be presented. In the first example, the processes of work hardening in Mo at room tempera ture will be presented. These studies have improved our understanding of di slocation mobility, dislocation generation, and dislocation-obstacle intera ctions. Zn the second example, the interaction of matrix dislocations with grain boundaries will be described. From such studies predictive criteria f or slip transfer through grain boundaries have been developed. (C) 2001 Els evier Science B.V. All rights reserved.