Project Details
Projekt
Mechanical Behaviour of Nanoporous Gold: Influence of Morphology
Subject Area
Mechanical Properties of Metallic Materials and their Microstructural Origins
Term
from 2012 to 2015
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 222106505
Nanoporous Au is a metal foam composed of fully connected nanoscale ligaments that can be reproducibly synthesized by chemical dissolution of Au-Ag alloys. Recently, it has been observed that nanoporous Au shows a lower modulus and higher strength than expected from classical foam scaling laws, and is extremely brittle despite the high ductility of Au. This counter-intuitive behaviour presumably lies in the unusual morphology of the nanoporous foam and in the small dimensions of the ligaments. In order to identify the exact origins of the observed mechanical behaviour, direct comparisons between structure and mechanical properties of nanoporous Au foams will be performed by a combination of experiment and modelling. The structure of nanoporous Au samples with ligament diameters between 30 and 500 nm will be determined by serial sectioning in a focused ion beam microscope and used as a basis for finite element modelling of the mechanical properties. The modelled modulus and flow stress will be compared with experimental micro-mechanical tests on the same material. By also performing serial sectioning on deformed samples, we aim to determine which features of the foam morphology control the deformation and to develop a length-scale dependent constitutive model for nanoscale Au. This understanding will aid in developing guidelines for foam optimisation and for developing dislocation-based models of deformation in nanoscale metal volumes.
DFG Programme
Research Grants
