Year of Publication

2015

Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation

College

Engineering

Department

Chemical and Materials Engineering

First Advisor

Dr. T. John Balk

Abstract

Nanoporous metals have recently been drawn significant interest in various fields of research. Their high surface-to-volume ratio present a strong potential for applications in sensing, catalysis, micro-electromechanical systems (MEMS) and even in the medical field. However, the mechanical properties of nanoporous metals have not yet been well determined, as conducting mechanical tests was found to be challenging. Scaling relations linking the mechanical properties of porous materials to those of their dense counterparts are successfully and widely used for many porous metals. However, their applicability to nanoporous metals have recently been questioned, as estimations from the classic scaling relations were found no to agree with experimental determinations.

In this study, the mechanical properties of nanoporous gold will be measured by conducting tensile testing of single crystalline, millimeter-scale specimens, for the first time. Results did not agree with the predictions from the classic scaling relations. Using experimental results from these tensile tests, new nanoindentation testing and data reported in the literature, a new scaling relation for the yield strength of nanoporous gold is proposed. This new relation is found to correctly describe the mechanical properties of nanoporous gold. In addition, compression tests are conducted on polycrystalline nanoporous gold, and the results were found to agree very well with the proposed scaling relation.

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