Regensburg 2019 – wissenschaftliches Programm
MM 28.2: Vortrag
Mittwoch, 3. April 2019, 15:30–15:45, H45
Electron beam-induced rejuvenation in amorphous TiAl during in-situ TEM deformation — Christian Ebner1, Jagannathan Rajagopalan2, Christina Lekka3, and •Christian Rentenberger1 — 1University of Vienna, Physics of Nanostructured Materials, Vienna, Austria — 2Arizona State University, Department of Materials Science and Engineering, Tempe, USA — 3University of Ioannina, Department of Materials Science and Engineering, Ioannina, Greece
In-situ transmission electron microscopy (TEM) facilitates the combined study of structure and fundamental mechanical properties at the nanometer scale. With the advancement in tools, methods and evaluation the sensitivity of measurements became increased. We show that electron irradiation of amorphous TiAl thin films under external tensile stress results in structural rejuvenation and a characteristic change of the elastic properties over time as measured by the atomic-level elastic strain contained in the TEM diffraction pattern. Deeper insights into the property changes triggered by the electron beam and resulting in the observed material response are gained via classical molecular dynamics simulations. These simulations reveal a beam-induced change in quantities like mean atomic volume, potential energy and atomic vibrational mean square displacement. The direct link to the experimental data is established by the calculation of diffraction pattern based on the simulated atomic structure.
Financial support by the Austrian Science Fund FWF: I1309 is acknowledged.