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MM: Fachverband Metall- und Materialphysik
MM 27: Topical Session: Interface-dominated phenomena - Nanoporous Metals
MM 27.3: Vortrag
Dienstag, 17. März 2020, 14:45–15:00, IFW A
Coarsening of nanoscale metal networks and their connectivity evolution via kinetic Monte Carlo simulations — •Yong Li1,2, Bao-Nam Dinh Ngo2, Jürgen Markmann2,1, and Jörg Weissmüller1,2 — 1Institute of Materials Physics and Technology, Hamburg University of Technology, Hamburg, Germany — 2Institute of Materials Research, Materials Mechanics, Helmholtz-Zentrum Geesthacht, Geesthacht, Germany
Nanoporous gold made by dealloying takes the form of a network assembled from nanoscale struts or "ligaments". It has been emphasized that the connectivity of the networks is decisive for their mechanical behavior. The relevant experimental observations lead to apparently contradictory conclusions on how the connectivity evolves during coarsening. Here, we study the microstructure evolution of nanoscale metal network structures due to surface diffusion during annealing, using large-scale on-lattice kinetic Monte Carlo simulation and spinodal-like initial microstructures. Our results [Y. Li et al., Phys Rev Mater 3 (2019) 076001.] confirm the classical time exponent t1/4 for the size evolution. They also reveal that the degree of surface faceting does not affect the growth kinetics or the evolution of connectivity. The initial connectivity, as described by a scaled topological genus, depends on the solid fraction, ϕ, of the microstructure. Furthermore, networks with ϕ 0.30 undergo a self-similar coarsening and maintain their connectivity, whereas networks with ϕ < 0.30 lose their connectivity during coarsening and will eventually disintegrate into isolated clusters.