Year of Publication
Doctor of Philosophy (PhD)
Chemical and Materials Engineering
Dr. T John Balk
Nanoporous (np) metals and alloys are the subject of increasing research attention due to their high surface-area-to-volume ratio. Numerous methods exist to create np metals, with dealloying being a common approach. By dissolving one or more elements from certain alloy systems, porous structure can be generated. Utilizing this method, multiple np metals, including np-Ni, np-Ir, and np-Au were created. By carefully adjusting precursor type and dealloying conditions for each system, nanoporous Ni/Ir/Au with different morphologies and even controllable ligament/pore size were achieved.
The mechanical behavior of porous materials is related to their fully dense counterparts by scaling equations. Established scaling laws exist and are widely applied for low relative density, micro- and macro-scale open-cell porous materials. However, these laws are not directly applicable to nanoporous metals, due to higher relative density and nanoscale cells. In this study, scaling laws were reviewed in light of the thermomechanical behavior of multilayer np-Ir thin films subjected to thermal cycling. Thermal cycling allows measurement of biaxial modulus from thermoelastic segments, and also causes film thickness to contract, with increases in relative density. A modified scaling equation was generated for biaxial modulus of np-Ir, and differed significantly from the classic equation.
Wang, Lei, "STRUCTURAL TAILORING OF NANOPOROUS METALS AND STUDY OF THEIR MECHANICAL BEHAVIOR" (2013). Theses and Dissertations--Chemical and Materials Engineering. 22.