Regensburg 2019 – wissenschaftliches Programm
MM 28.1: Topical Talk
Mittwoch, 3. April 2019, 15:00–15:30, H45
Towards understanding dislocation based plasticity in high entropy alloys by in-situ TEM — •Gerhard Dehm — Max-Planck-Institut für Eisenforschung GmbH
Dislocation-based deformation mechanisms of high entropy alloys (HEAs) remain elusive and require a fundamental understanding in order to tailor their mechanical properties. Since HEAs have five or more constituent elements close to the equiatomic ratio with a stable single phase, their plastic deformation is expected to be different compared to conventional alloys. Here, we present a study correlating the microstructure and dislocation plasticity of a single crystalline FeCrCoMnNi FCC single phase HEA by employing in-situ transmission electron microscope (TEM) compression and tensile deformation. Moreover, an atomic-scale chemical analysis is conducted by aberration-corrected scanning TEM energy dispersive X-ray spectroscopy (STEM-EDS) and atom probe tomography to investigate chemical inhomogeneity, for example, precipitate formation or local inhomogeneity. The aims of the study are understanding of dislocation plasticity in a FCC HEA, investigation of nanometer-scale elemental distribution and measurement of mechanical properties of FCC HEA submicron pillars. Acknowledgements: Major contributions by S. Lee, W. Lu, C. Kirchlechner, R. Raghavan, Z. Li, J. Duarte, S.H. Oh, D. Raabe and C. Liebscher are gratefully acknowledged.