Berlin 2018 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 39: Topical session (Symposium EPS and MM): Mechanical Properties at Small Scales

MM 39.4: Vortrag

Mittwoch, 14. März 2018, 16:00–16:15, H 0107

Mechanical properties of nanoporous gold - impact of solid fraction — •Birthe Zandersons¹, Lukas Lührs¹, and Jörg Weissmüller^1,2 — ¹Institute of Materials Physics and Technology, Hamburg University of Technology — ²InstitInstitute of Materials Physics and Technology, Hamburg University of Technologyute of Materials Research, Materials Mechanics, Helmholtz-Zentrum Geesthacht

Nanoporous gold (NPG) is an attractive model system for studies of small scale mechanical behavior. Its centimeter-sized open porous bodies are structured by a monolithic network of struts or ”ligaments”. The ligament size can be tuned in the range of a few to several hundred nanometer. In the last years several studies find the mechanical behavior of NPG reproducible and highly consistent, except that the results fall in groups of substantially different strength. A widespread theory connects these differences to the variation of solid fraction due to different preparation. Here, we present a systematic investigation of the influence of preparation for the mechanical properties of NPG, using the most common preparation methods. Precursor alloys Au_xAg_100−x with x=20,25,30,35 are dealloyed electrochemically in 1 M HClO₄ and with free corrosion in concentrated HNO₃. Using continous loading and load/ unload compression tests we investigate the stress-strain behaviour, Young’s modulus and Poisson’s ratio and confirm substential differences depending on the initial alloy composition.