Alexandre Mussi: Latest developments in electron tomography of dislocations: from 3D to 4D, 3D to mechanics, and TEM to SEM

Abstract

Rigorous analyses of dislocation microstructures are necessary to conduct fundamental studies of plastic deformation mechanisms. These characterizations make it possible to determine the Burgers vectors and habitat planes (climb and/or slip) of dislocations, which are essential data for providing crystal plasticity models. For simple microstructures where a few slip-systems are active, characterizations using weak-beam dark-field conventional transmission electron microscopy are sufficient. This is not the case when microstructures are complex (high dislocation density, multiple interactions, climb, slip, cross-slip, etc.), which give dislocations 3D configurations. Dislocation tomography is then essential for deciphering these microstructures. During this seminar, I will present the methodology for performing dislocation tomography, the latest advances in this field (such as combining tomography with mechanics, the development of 4D and dislocation tomography using the SEM), and results that would have been difficult to obtain without the use of this technique.

About the speaker

Alexandre Mussi is an Assistant Professor at the Unité Matériaux et Transformations (UMET) laboratory of the University of Lille, affiliated with the CNRS. His research focuses on the plasticity and deformation mechanisms of Earth’s mantle minerals, especially in subduction zone contexts, using advanced transmission electron microscopy (TEM) techniques.

By videoconference

The seminar will also be accessible via videoconference on Microsoft Teams.