Uniaxial compression testing of bulk nanoporous gold

Abstract

The mechanical properties of bulk nanoporous gold (np–Au) with a relative density of 0.35 were investigated by compression testing of millimetre-scale specimens. Young’s modulus, Poisson’s ratio and yield strength values were determined from uniaxial, quasi-static experiments using a custom-built mechanical testing system. The cuboid-shaped specimens were fabricated following a specific, controlled process (including cutting and grinding) that guaranteed a precise and repeatable geometry. The np–Au structure was created from a silver–gold alloy by electrochemical dealloying in nitric acid. Mechanical properties obtained from compression testing are compared to values reported in the literature and to scaling relations. Values are found to agree with a recently proposed scaling relation for the yield strength of np–Au that incorporates a ligament size effect and a modified scaling exponent.

Keywords:

• Nanoporous gold
• mechanical properties
• compressive testing
• scaling law
• material behaviour

Acknowledgements

This material is based upon work supported by the National Science Foundation under grant number DMR-0847693. The authors thank Karl Sieradzki for helpful discussions on the deformation behaviour of nanoporous gold.