| Abstract Scope |
Nanoporous gold(np-Au) is material composed of continuously connected ligament and pore. Due to low density and high surface area-to-volume ratio, np-Aus apply to catalyst, actuator, and sensor. However, np-Au has brittle behavior as an issue to be overcome. Brittleness and flaw-sensitivity appear because pore acts as stress concentration site and ligaments are sequentially failed right after crack nucleation. Grain boundary is, also, another cause of stress concentration, so early crack nucleation is observed in grain boundary. For the enhancement of flaw-tolerance, we focus on grain size and grain morphology to activate grain boundary plasticity. We prepare np-Aus with coarse grain, fine grain, and anisotropic grain structure. Fracture toughness is measured with single edge notched tension(SENT), and flaw-tolerance is investigated by micro tensile test and digital image correlation (DIC) method.
This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (2020R1A5A6017701 and 2021R1F1A1051001). |