Dresden 2017 – wissenschaftliches Programm
MM 39: Topical session: Interface-Controlled Microstructures: Mechanical Properties and Mechano-Chemical Coupling - Structure and deformation III
MM 39.3: Vortrag
Mittwoch, 22. März 2017, 10:45–11:00, IFW B
Impact of the composition of Au-Ag alloys on the mechanical properties of dealloyed nanoporous gold — •Birthe Müller1, 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) made by dealloying can be viewed as a nanofoam that consists of interconnected nanoscale pores and solid ”ligaments” that can take the shape of macroscopic bodies. Due to its tunable feature size from a few to a several hundred nanometers and its high chemical stability NPG has proven an attractive model system for various small scale studies. E.g. the mechanical properties of NPG have been the subject of a multitude of studies over many years. Analog to macroscopic metallic foams, results are frequently linked to the solid fraction, φ. Focusing on φ, the influence of the initial composition of precursor alloy and the manufacturing methods are often neglected.
We present a comparative study on the mechanical properties of NPG using varying initial compositions and different processing procedures. AuxAg100−x precursors with x=20,25,30,35 were synthesized via electrochemical dealloying in 1 M HClO4 as well as free corrosion in concentrated HNO3. Using compression tests with single loading and load/unload protocols we investigate the stress-strain behavior, the Young’s modulus and the Poisson’s ratio. We find significant differences in the mechanical responses that contradict the image of a φ controlled behavior.