Abstract
We investigated the indentation response of Ta/Ti nanocomposite thin films with widely differing morphologies of the constituent phases, ranging from particulate to bicontinuously interpenetrating, but comparable characteristic dimensions of microstructure features. We find no influence of microstructure morphology on stiffness or hardness. However, we see a systematic dependence of indentation pileup height on microstructure morphology, with the largest pileups observed in composites with connected, Ta-rich networks and lowest for highly connected, Ti-rich networks. We attribute this dependence to an influence of microstructure morphology on strain hardening rates and propose mechanisms to explain it.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 5677-5690 |
| Number of pages | 14 |
| Journal | Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science |
| Volume | 51 |
| Issue number | 11 |
| DOIs | |
| State | Published - Nov 1 2020 |
Funding
This work was supported by the NSF DMREF program under Grant #1623051. We thank J. K. Baldwin for thin-film deposition and both G. Pharr and B. Crawford for helpful discussions regarding indentation pileup and the impact of an underlying substrate. 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. Use of the TAMU Materials Characterization Facility is acknowledged.
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys