SKM 2023 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 23: Poster II
MM 23.23: Poster
Dienstag, 28. März 2023, 18:15–20:00, P2/OG1+2
Negative Poisson's Ratio in Hierarchical Nanoporous Gold — •Haonan Sun1,2, Lukas Lührs2, 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 Materials Mechanics, Helmholtz-Zentrum Hereon, 21502 Geesthacht, Germany
The recent fabrication of crack-free monolithic hierarchical nested network nanoporous gold enables the investigation on the benefits of hierarchy in the aspect of mechanical properties [1]. 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 the hierarchical structure on Poisson's ratio is not explored yet. In this work, we synthesize mm-sized HNPG samples out of a Ag93Au7 master alloy with a dealloying-coarsening-dealloying method. We then explore the elastic and plastic Poisson*s ratios of HNPG by using digital image correlation during compression testsing. Remarkably, we find Poisson*s ratio of HNPG is negative for a given strain regime, which suggests their potential application as auxetic materials. Furthermore, the effect of ligament size at both hierarchy levels on Poisson*s ratio is also investigated. [1] S. Shi, Y. Li, B.-N. Ngo-Dinh, J. Markmann and J. Weissmüller, Scaling behavior of stiffness and strength of hierarchical network nanomaterials, Science 371 (6533), 2021.