Compliant nanoporous gold is investigated with regards to its elastic modulus and deformation mechanisms. Samples are fabricated by dealloying AgAu alloys at elevated temperature and reduced dealloying potential compared with conventional methods in the literature. This procedure minimizes cracking and shrinkage that is typical from other dealloying methods. Furthermore, samples are found to be more compliant while immersed in water. Samples were tested in cyclic compression using a piezoelectric compression rig. Testing showed that the wet samples become stiffer upon drying and the effect is reversible with short drying times. This is attributed to microstructural effects as the ligament network becomes more connected as a result of drying, effectively shifting the dominant deformation mode from three-point bending to cantilever bending. At longer dry times, the effect is irreversible due to contact weld formation. Preliminary results on sputter deposited AgAuPt alloys show altered dealloying kinetics and crack formation.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/18259 |
| Date | 13 January 2010 |
| Creators | Choi, Steven Lawrence |
| Contributors | Newman, Roger C., Thorpe, Steven J. |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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