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MM: Fachverband Metall- und Materialphysik

MM 6: Topical Session TEM II

MM 6.3: Talk

Monday, March 14, 2011, 15:15–15:30, IFW A

Metadislocations in Complex Metallic Alloys: A High-Resolution Scanning Transmission Electron Microscopy Study — •Marc Heggen, Lothar Houben, and Michael Feuerbacher — Ernst Ruska Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Juelich GmbH, D-52425 Juelich, Germany

Metadislocations are highly complex defects which involve several hundreds of atoms in their core. We present a microstructural investigation on Metadislocations using aberration-corrected high-resolution scanning transmission electron microscopy. A novel and highly complex deformation mechanism is found which is based on the movement of a metadislocation core mediating strain and separate escort defects [1]. Upon deformation, the escort defects move along with the metadislocation core and locally transform the material structure. This mechanism implies the coordinated movement of hundreds of atoms per elementary step. Although the mechanism is very complex, it can be described by a simple jigsaw-puzzle-like rearrangement of basic structural subunits.

[1] M. Heggen, L. Houben, M. Feuerbacher, Nature Materials 9 (2010) 332.