Mechanical response of nanoporous gold

By D. Farkas, Alfredo Caro, Eduardo M. Bringa, D. Crowson. 2013

150 citations recorded by the source corpus.

Abstract We report the results of computational tensile and compressive tests for model bi-continuous nanoporous gold structures using atomistic simulations with empirical many-body potentials and molecular dynamics. The results are compared with the predictions of scaling laws for coarser-scale foams and with available experimental data. We find a surprising substantial tension/compression asymmetry in yield due to the surface stress that sets the filament under compression, providing a bias favoring yielding in compression. We provide a model for our results based on a ligament strength value close to the theoretical strength of Au, and the surface stress. The model predicts a significant tension/compression asymmetry for ligament sizes below ∼10 nm and pore collapse for ligament sizes below 1 nm. We also observe an unexpected compaction tendency under tension characterized by a decrease in the total volume of the sample of 15% for samples deformed under tension by 30%. The mechanism of the compaction involves a decrease in the average pore size and pore collapse resulting from plasticity within the ligaments.

Subfields: Materials Chemistry, Renewable Energy, Sustainability and the Environment

View Paper: https://www.semanticscholar.org/paper/c19d7b60e2dac78f052ad57af525acd15d0ecd02

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In Materials Chemistry

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Citations in the corpus

Nanoporous Gold—Testing Macro-scale Samples to Probe Small-scale Mechanical Behavior (2016, methodology): “In situ observations of the effective elastic response during potential cycles on NPG-based hybrid materials explore the impact of the local elastic behavior at the surface for the effective stiffness of NPG.”
3D stochastic bicontinuous microstructures: generation, topology and elasticity (2018, background): “That data underlines the findinge highlighted in the experimental studies and confirmed by atomistic simulation [19,55,56] of nanoporous gold e that the material is generally more compliant than predicted by the GibsonAshby law.”
Generation of 3D representative volume elements for heterogeneous materials: A review (2018, methodology): “A common method for modeling high quality nanoporous (open-cell) metallic microstructures is simulating the kinetics of phase evolution with phase separation during dealloying and coarsening via Ginzburg-Landau and Cahn-Hilliard equations [501,284,285,502].”
Anomalous Compliance and Early Yielding of Nanoporous Gold (2015, methodology): “and FEM [19, 20], with FEM linking the observation to microstructural disorder [20].”