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MM: Fachverband Metall- und Materialphysik

MM 30: Poster Session II

MM 30.7: Poster

Dienstag, 17. März 2020, 18:15–20:00, P4

Correlative study of grain boundary segregation in nanocrystalline copper–nickel alloys — •Felix Fischer, Rüya Duran, Guido Schmitz, and Sebastian Eich — Institute for Materials Science, University of Stuttgart, Germany

Nanocrystalline material properties are dominated by grain boundaries (GB). In nanocrystalline copper–nickel alloys, which have high corrosion resistance, thermal conductivity, and fabricability, segregation of copper to GBs is energetically preferred and was previously quantified in simulations by Molecular Dynamics using a new embedded-atom alloy potential. In these simulations, the values for the solute excess depend highly on the GB structure. Comparison to experimental data is required, thus correlative transmission electron backscattering diffraction (t-EBSD) and atom probe tomography (APT) measurements are carried out on prepared nanocrystalline tips.

t-EBSD allows an evaluation of the grain orientations and thus the GB types, while APT gives an atomically-resolved digital reconstruction of the measured tip. Combing these two methods, the segregation of copper to GBs can be correlated to the GB type, alloy concentration as well as the annealing temperature and furthermore compared to the simulated segregation.

Experimental as well as simulated segregation curves will finally be compared and described by a previously developed model for interface segregation. The change in interface formation energy based on the new model will be predicted.