%0 journal article
%@ 0264-1275
%A Wu, Y., Markmann, J., Lilleodden, E.T.

%D 2023
%J Materials & Design

%P 112175 
%R doi:10.1016/j.matdes.2023.112175
%T On the consequences of intrinsic and extrinsic size effects on the mechanical response of nanoporous Au
%U https://doi.org/10.1016/j.matdes.2023.112175
 
%X In this study, the consequence of intrinsic and extrinsic size effects on mechanical responses of nanoporous gold is investigated via microcompression testing. By varying the micropillar diameter (D) between 1 µm and 20 µm and the ligament size (L), 50 nm and 350 nm, a critical ratio (α = D/L = 20) was found, above which the test structure can be considered a representative volume element, resulting in identical mechanical response and uniform deformation. Below that value, both flow stress and elastic modulus decrease with decreasing pillar diameter, as evidenced for a measurement series with a fixed ligament size of 350 nm where the flow stress decreased by more than 50% (from approximately 5 to 2.5 MPa) and the elastic modulus was reduced from approximately 0.5 GPa to almost zero. Stochastic behavior along with non-uniform deformation and failure is observed for α < 10, suggesting that the size of the load-bearing units in this material is about 10 times the corresponding ligament size.