Regensburg 2025 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 36: Mechanical Properties
MM 36.8: Vortrag
Freitag, 21. März 2025, 12:15–12:30, H23
Scaling behavior of Poisson's ratio in hierarchical nanoporous materials — •Haonan Sun1,2, Lukas Lührs2, Wei-che Chang3, and Shan Shi1,3 — 1Research Group of Integrated Metallic Nanomaterials Systems, Hamburg University of Technology, 21073 Hamburg, Germany — 2Institute of Materials Physics and Technology, Hamburg University of Technology, 21073 Hamburg, Germany — 3Institute of Hydrogen Technology, Helmholtz-Zentrum Hereon, 21502 Geesthacht, Germany
The recent fabrication of crack-free monolithic hierarchical nested network nanoporous gold allows the investigation of the benefits of hierarchy in the aspect of mechanical properties at the nanoscale. It has been demonstrated that hierarchical nanoporous gold (HNPG) can achieve a substantially reduced solid fraction and enhanced specific stiffness and strength compared with non-hierarchical nanoporous gold. However, the role of hierarchical structure on Poisson's ratio has not been investigated yet. In this work, mm-sized HNPG samples are made out of an Ag93Au7 master alloy by a dealloying-coarsening-dealloying method. We then explore the elastic and plastic Poisson*s ratios of HNPG by using digital image correlation during compression tests. Remarkably, a scaling law of the elastic Poisson's ratio in hierarchical nanoporous materials with respect to the solid volume fraction is proposed and excellently supported by our experiments. This work enriches the understanding on the relationship between mechanical properties and microstructure in hierarchical network materials at the nanometer scale.
Keywords: Poisson's ratio; hierarchical nanoporous gold; dealloying; scaling law; mechanical property