Regensburg 2019 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 17: Nanomaterials
MM 17.2: Talk
Tuesday, April 2, 2019, 10:30–10:45, H46
Impact of the initial alloy composition on the mechanical properties of nanoporous gold — •Birthe Zandersons1, Lukas Lührs1, and Jörg Weissmüller1,2 — 1Institute of Materials Physics and Technology, Hamburg University of Technology — 2Institute of Materials Research, Materials Mechanics, Helmholtz-Zentrum Geesthacht
Nanoporous gold (NPG) is an attractive model system for small scale material behavior. The feature size of the chemical stabile, network like structure is tunable from a few to several hundred nanometers. Remarkable are clear distinctions in stiffness and strength, occurring by variations of the solid fraction, φ. Yet, due to different processing approaches, the published data are restricted in comparability. A comparative study of the initial composition of precursor alloys, which controls φ, and the processing steps is indispensable.
We systematically varied the alloy composition of AuxAg100−x, with x=20, 25, 30, 35 and we also varied the dealloying procedure with electrochemical corrosion in 1M HClO4 and free corrosion in concentrated HNO3. Using compression tests with continuous loading and load/ unload protocols, we explored the stress-strain behavior, Young‘s modulus and Poisson‘s ratio, emphasizing comparability. We confirm significant dependences on the master alloy compositions and show a database of the variation of the mechanical response with φ for a given ligament size and push the current approaches to stiffness and strength of nanoscale metal networks forward.