FABRICATIONS AND MECHANICAL PROPERTIES OF SUPER STRONG FUNCTIONAL NANOSTRUCTURES

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The functionality, lifetime, and commercial success of nanoelectronics ultimately depend on our ability to successfully design and engineer the mechanical properties of the small scale structures that comprise them. To that end, it is imperative to gain a fundamental understanding of the physical properties and reliability of nanoelectronics as a function of size in the sub-micron to nanometer scales. However, strengthening techniques that work well in bulk are often difficult to implement at the nanoscale level. For example, bulk nanocrystalline Ni specimens exhibit superior mechanical strength, but because of the grain boundary sliding, they soften when the sample is reduced to smaller than 100 nm. Conversely, well annealed single crystalline structures, which are soft in bulk, exhibit superior mechanical strength as the sample dimension decreases. Some proposed mechanisms recently suggested to explain this strength size effect include the dislocation starvation effect, stochastic behaviors, and nano-twin formations. These mechanism theories are unique to nanostructures; however, they are still in their infancy and need further development. This study has three objectives: 1) explore the alloying and precipitation effects on the mechanical properties of metallic nanostructures; 2) investigate the carbon nanotube-metal matrix nanocomposite mechanical deformation behaviors; and 3) develop guidelines to fabricate super-strong nanostructures. The proposed project will be conducted in our research facility using a state-of-the-art in-situ nanoindenter installed within a field-emission scanning electron microscope. This is believed to be the first and only in-situ nanoscale mechanical testing instrument in Canada, and one of only a few in the world. We anticipate that the proposal project will lead to an in-depth understanding of the solute/precipitation effect and the CNT influences on the strength of nanostructures, making it possible to develop structures that are strong and able to fulfill the functional behaviors.