Nanoporous (NP) metals are three-dimensional networks of inter-connected pores and ligaments. Their open-cell structure and high surface area per unit volume give them unique electrical, mechanical, and catalytic properties. These properties make NP metals excellent candidates for a variety of high-tech applications including catalysts for fuel cells, gas filtration, biosensors, and actuators. The performance of NP structure in all these applications is connected to its mechanical properties and deformation behavior during operation. For example, NP Au shows limited macroscopic ductility due to lack of strain hardening. The brittle fracture of NP Au can harm its interconnected structure and cause loss of functionality in many applications especially under cyclic loading. This project will use computational simulation methods to investigate the deformation behavior of nanoporous gold structure and determine the microstructure conditions under which NP Au exhibits ductile behavior and high strength for use in structural and functional applications. These results will be compared with available experimental investigations of the mechanical behavior of NP Au. The project will contribute to the education of students in the area and the PI will encourage students from underrepresented groups to pursue careers in STEM areas.
The proposed project will develop mathematical models and deformation maps that enable design of Nanoporous gold (NP Au) with improved mechanical properties. The research team will test the hypothesis that varying the morphological configuration of NP Au can enhance its ductility and strength. In pursuit of this goal, atomic-level simulations will be performed to understand the underlying mechanisms that control plastic deformation in NP Au. The role of structural and morphological parameters including surface and interface effects, ligament and pore sizes, orientation and loading direction, effect of triple junctions, density of pores and ligaments, surface ledges, and voids will be determined. The PI and her team will integrate their findings into deformation maps and mathematical models that relate the deformation mechanisms to structural parameters and predict the morphologies that result in to enhanced ductility and strength. These predictions will be compared with available experimental investigations of the mechanical behavior of NP Au. The project will contribute to the education of students in the area and the PI will encourage students from underrepresented groups to pursue careers in STEM areas.
