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Joshua Stuckner1 Katherine Frei1 Mitsu Murayama1

1, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States

Nanoporous metals such as nanoporous gold (NPG) exhibit nanoscale ductility but appear macroscopically brittle due to significant strain localization and subsequent fracture. Quantifying the morphology evolution and location of strain during deformation of this three-dimensional networked material may give further insight into the cause of strain localization and also validate similar simulation experiments through comparison. We investigate the microstructure response to tensile stress of NPG films consisting of ligament and pore sizes of approximately 10 nm through in-situ scanning electron microscope (SEM) and transmission electron microscope (TEM) tensile tests. SEM datasets of these tests were used to track and quantify the evolution of ligament and pore morphology during deformation. The change in diameter, length, orientation, aspect ratio, and area fraction was calculated for the pores and ligaments on a frame-to-frame basis using automatic image analysis. The location and extent of strain was also observed. TEM datasets revealed the dislocation and strain field activity in NPG during deformation. Thus, the combination of SEM and TEM in-situ experiments allowed for a direct comparison of lattice deformation mechanisms and broader nanoscale ligament and pore morphology evolution. These experiments form a baseline for quantifiable comparison with simulated mechanical testing and future improvements to experimental samples.

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