Catastrophic vs Gradual Collapse of Thin-Walled Nanocrystalline Ni Hollow Cylinders As Building Blocks of Microlattice Structures
Abstract
Lightweight yet stiff and strong lattice structures are attractive for various engineering applications, such as cores of sandwich shells and components designed for impact mitigation. Recent breakthroughs in manufacturing enable efficient fabrication of hierarchically architected microlattices, with dimensional control spanning seven orders of magnitude in length scale. These materials have the potential to exploit desirable nanoscale-size effects in a macroscopic structure, as long as their mechanical behavior at each appropriate scale – nano, micro, and macro levels – is properly understood. In this letter, we report the nanomechanical response of individual microlattice members. We show that hollow nanocrystalline Ni cylinders differing only in wall thicknesses, 500 and 150 nm, exhibit strikingly different collapse modes: the 500 nm sample collapses in a brittle manner, via a single strain burst, while the 150 nm sample shows a gradual collapse, via a series of small and discrete strain bursts. Further, compressive strength in 150 nm sample is 99.2% lower than predicted by shell buckling theory, likely due to localized buckling and fracture events observed during in situ compression experiments. We attribute this difference to the size-induced transition in deformation behavior, unique to nanoscale, and discuss it in the framework of "size effects" in crystalline strength.
Additional Information
© 2011 American Chemical Society. Received: May 31, 2011. Revised: August 12, 2011. Publication Date (Web): August 18, 2011. The authors gratefully acknowledge the financial support of DARPA through MCMA program, contract no. W91CRB-10C-0305. The authors are grateful to Emily Warmann for helping on XRD work and Sophia Yang for help with sample fabrication. The authors also gratefully acknowledge helpful discussions with John Hutchinson and Mike Baskes.Attached Files
Supplemental Material - nl202475p_si_001.pdf
Supplemental Material - nl202475p_si_002.avi
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Additional details
- Eprint ID
- 27802
- DOI
- 10.1021/nl202475p
- Resolver ID
- CaltechAUTHORS:20111116-101311984
- Army Research Office (ARO)
- W91CRB-10C-0305
- Defense Advanced Research Projects Agency (DARPA)
- Created
-
2011-11-16Created from EPrint's datestamp field
- Updated
-
2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Kavli Nanoscience Institute