Dresden 2020 – wissenschaftliches Programm
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MM 8.1: Vortrag
Montag, 16. März 2020, 11:45–12:00, IFW B
Crystalline-amorphous interfaces in high entropy alloy nanolaminates produced via high-pressure torsion — •Shabnam Taheriniya1, Farnaz A. Davani1, Sven Hilke1, Harald Rösner1, Marilena Tomut2, Sergiy V. Divinski1, and Gerhard Wilde1 — 1Westfälische Wilhelms-Universität Münster, Münster, Germany — 2GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany
The intermixing possibilities of dissimilar high entropy alloys and the effect of co-deformation on microstructure evolution were investigated. High pressure torsion (HPT) was applied for bonding separate disks of equiatomic FCC single-phase CoCrFeMnNi and BCC HfNbTaTiZr alloys. The samples were processed for 5, 10 and 15 revolutions at ambient temperature under 9 GPa pressure. The resulting composite material showed enhanced mechanical properties as compared to either HEA systems processed under similar conditions. Scanning electron microscopy and energy-dispersive spectroscopy (EDS) revealed heterogeneous microstructures with relatively sharp chemical interfaces. After large strain, the BCC HfNbTaTiZr phase exhibited significant phase separation into Ta-rich and Ta-poor regions. Moreover, the processed samples possessed a nanolamellar microstructure and vortex-like regions. A partial amorphisation of the BCC phase was observed by transmission electron microscopy.