Dresden 2020 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 40: Topical Session: Interface-dominated phenomena - Solutes at Interfaces I

MM 40.3: Talk

Wednesday, March 18, 2020, 16:30–16:45, IFW A

Correlative study of grain boundary segregation in nanocrystalline copper-nickel alloys — •Felix Fischer, Rüya Duran, and Guido Schmitz — 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. In these simulations the values for excess segregation depend highly on grain boundary structure, therefor transmission electron backscatter 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 simulated segregations. By applying molecular dynamic simulations, additionally, the excess segregations of so far unevaluated GBs can be obtained and directly compared to experimental results.

The presentation will elucidate in detail the experimental procedure and shortly mention the used simulation methods from which the correlations of GB segregation to GB type, concentration and temperature are determined and also compared between theory and experiment.