Abstract
When attempting to measure material properties by sampling near-surface volumes with techniques like nanoindentation, careful consideration of the state of the surface compared to the bulk is paramount for valid characterization. The process of surface planarization of glass in preparation for analysis is no exception. Water's general reactivity with silicate glasses has been well-established, but under the typical conditions for mechanical polishing, the usual practical assumption is that the potential effects on measured mechanical properties are insignificant due to the short period of glass-water interaction and the non-extreme corrosive environment. On the contrary, in this study, it is shown that the act of polishing certain borosilicate glass compositions in an aqueous environment directly affects the nanomechanical response to several micrometers, reducing the measured elastic modulus and hardness by ~20% and ~35%, respectively. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) are used to confirm the formation of an altered, hydrated surface layer.
| Original language | English |
|---|---|
| Pages (from-to) | 302-306 |
| Number of pages | 5 |
| Journal | International Journal of Applied Glass Science |
| Volume | 10 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jul 2019 |
Funding
The authors extend their gratitude to the University of Tennessee, Knoxville from the US Army Research Office project W911NF-15-1-0614 under the direction of Program Manager D. Stepp for funding this work. We thank US Army Research Laboratory's P. Patel and S. Kilczewski for fabricating the glasses, and Oak Ridge National Laboratory's R. Parten for specimen machining, T. Geer for polishing support, and M. Lance for FTIR assistance.
Keywords
- aqueous polishing environment
- borosilicate
- indentation
- mechanical properties
- surface modification