Size Effects in Single-Crystal Metallic Micro- and Nanocubes
- 533 Downloads
We study the response of single-crystal metallic micro- and nanocubes under quasistatic compression using silver as the model material. Using a seed-growth process, we synthesized the defect-free single-crystal silver cubes of near-perfect cubic geometry with their size varying from 100 nm to 2 μm. We use a nanoindentor/scanning electron microscope system to measure the stress-strain behavior and correlate it to the deformation response seen in in-situ SEM imaging. The silver cubes plastically deform through spontaneous nucleation of dislocation-slips upon reaching their yield strength. The yield strength of silver cubes exhibits strong dependence on the sample size, where the decreasing sample size results in increasing yield strength. Our studies also reveal the effects of pre-existing dislocations on the governing deformation mechanisms: the samples containing dislocations exhibit a hardening behavior with slip events of stochastic nature in contrast to the spontaneous strain-burst seen in dislocation-free sample.
KeywordsSize-effects Silver microcubes Silver nanocubes Quasistatic compression Strain burst Stochastic response
We acknowledge the financial support from the George R. Brown School of Engineering of Rice University. This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is operated by Los Alamos National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy under contract DE-AC52-06NA25396.