| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
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| Symposium
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Deformation and Transitions at Grain Boundaries VII
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| Presentation Title |
Effect of Silica and Rare Earth Oxides on the Grain Boundary Chemistries in Hot-pressed Boron suboxide (B6O) and the Observance of Nanolayer Films |
| Author(s) |
Kristopher Behler, Christopher J. Marvel, Jerry C. LaSalvia, J. Dunn-Synowczynski, S.D. Walck, Martin Harmer |
| On-Site Speaker (Planned) |
Kristopher Behler |
| Abstract Scope |
Boron suboxide was hot-pressed using rare earth oxides and/or silica sintering aids. Small amounts of silica (1 vol.%) have shown improvements in the densification and hardness, while larger amounts have shown differing microstructures as observed by abnormal grain growth (AGG). The addition of 5 vol.% silica exhibits AGG at elevated temperatures suggesting a change in the grain boundary complexion. The addition of Y and La resulted in suppression of AGG, whereas, Yb promoted AGG. Observed differences in excess Si at the grain boundaries were measured using AC-STEM/EDS. While ordered monolayers of Y, La and Yb were observed, the Si appeared to be disordered. The addition of Eu, exhibited at least three chemically distinct grain boundary chemistries with varying amounts of Si:Eu ranging from Si-rich submonolayers to monolayers of Eu to ~1nm thick nanolayer films. Experimental results, DFT results and procedures will be presented. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |