Tensile and compressive microspecimen testing of bulk nanoporous gold

Nanoporous gold (np-Au) is a macroscopically brittle material, which poses difficulties for tensile testing of bulk specimens. By combining a fabrication approach that minimizes cracking in bulk np-Au and a microspecimen test technique that permits small testing volumes, both tension and compression tests were performed on sub-millimeter gage thicknesses of np-Au. Compressive strength was higher than tensile strength, as would be expected for a brittle material, but all strength values were significantly lower than literature values for nanoindentation testing. Measured elastic modulus was nearly the same in tension and compression, and was much lower than Gibson-Ash-by scaling relations would predict for porous gold with this density.