Regensburg 2016 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 40: Topical session: In-situ Microscopy with Electrons, X-Rays and Scanning Probes in Materials Science IV - Atomic structure and defects III

MM 40.1: Topical Talk

Wednesday, March 9, 2016, 15:45–16:15, H38

Mapping local transient strain fields during in situ TEM deformation — •Christoph Gammer — University of Vienna, Physics of Nanostructured Materials — NCEM, Molecular Foundry, Lawrence Berkeley National Laboratory

While in situ TEM has provided insight into fundamental deformation mechanisms, the local strain during plastic deformation is of great importance to correlate defect structure with material properties.

In the present work we show that strain mapping can be carried out during continuous in situ deformation in a TEM at the nanometer scale. Two different types of tests are demonstrated. In the case of crystalline samples, our method is based on STEM diffraction mapping [1,2]. A direct electron detector is used to acquire diffraction patterns at a faster rate. Time resolved strain maps recorded during in situ deformation of an Al sample allow to measure local and transient strains occurring around moving dislocations. In addition an amorphous metallic glass sample was deformed in tension. For this experiment digital image correlation of decorated samples was used to obtain the time dependent local strain map revealing extreme localization of the deformation.
1. C. Gammer et al., Ultramicroscopy 155 (2015) 1.
2. V.B. Ozdol et al., Appl. Phys. Lett. 106 (2015) 253107.
We acknowledge support by the Austrian FWF [J3397] and the Molecular Foundry, U.S. Dept. of Energy, Contract #DE-AC02-05CH11231.