Berlin 2024 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 25: Interface Controlled Properties, Nanomaterials and Microstructure Design IV
MM 25.3: Talk
Tuesday, March 19, 2024, 12:15–12:30, C 230
Nano-scale investigation of fractal abnormal grains and grain boundaries in Pd-Au using atom probe tomography — •Johannes Wild1, Torben Boll1,2,3, Fabian Andorfer4, Svetlana Korneychuk2,3, Jules M. Dake4, Dorothée Vinga Szabo1,2,3, Stefan Wagner1, Carl E. Krill III4, and Astrid Pundt1,2 — 1Institute for Applied Materials (IAM-WK), Karlsruhe Institute of Technology — 2Institute of Nanotechnology (INT), Karlsruhe Institute of Technology — 3Karlsruhe Nano Micro Facility (KNMFi), Karlsruhe Institute of Technology — 4Institute of Functional Nanosystems, Ulm University
Nanocrystalline (NC) Pd-Au prepared by inert gas condensation exhibits fractal abnormal grain growth during heat treatment. The resulting microstructure is characterized by a bimodal grain size distribution with micrometer-sized grains (FG) embedded in a matrix of NC grains (NG). To elucidate this unusual manifestation of grain growth, we extracted sharp tip samples from FG and NG bulk regions, as well as from the FG-FG and FG-NG interface regions and analysed them with a LEAP 4000X HR atom probe. The NG region exhibited an O content that was multiple times higher in comparison with the FG region. Cluster analysis confirmed the presence of a multitude of O-rich clusters in the NG, but not in the FG region. Furthermore, the reconstructions of the boundary regions revealed an unexpected diversity of host and contamination element distributions at the FG-FG and FG-NG interfaces.
Keywords: abnormal grain growth; fractal; atom probe tomography