Nanolaminate composites show promise as high strength and toughness materials. However, due to the limited volume of these materials, micron scale mechanical testing methods must be used to determine the properties of these films. To this end, a novel approach combining a double notch shear testing geometry and compression with a flat punch in a nanoindenter was developed to determine the mechanical properties of these films under shear loading. To further elucidate the failure mechanisms under shear loading, in situ TEM experiments were performed using a double notch geometry cut into the TEM foil. Aluminum layer thicknesses of 50. nm and 100. nm were used to show the effect of constraint on the deformation. Higher shear strength was observed in the 50. nm sample (690±54. MPa) compared to the 100. nm sample (423±28.7. MPa). Additionally, failure occurred close to the Al-SiC interface in the 50. nm sample as opposed to failure within the Al layer in the 100. nm sample.
Bibliographical noteFunding Information:
The authors would like to acknowledge the National Science Foundation Materials World Network (Contract DMR-1209928 , Dr. Lynnette Madsen, Program Manager) for financial support of this research and the LeRoy Erying Center for Solid State Science for the use of their microscopy facilities. 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 . We also thank Sudhanshu S. Singh for help with the nanoindenter, and Katie Jungjohann for help with the TEM at CINT.
© 2014 Elsevier B.V.
- Focused ion beam (FIB)
- Nanostructured materials
- Shear testing
- Transmission electron microscope (TEM)