About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
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| Symposium
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Advancing the Frontier of Powder Materials Processing and Sintering: A MPMD/EPD Symposium in Honor of Eugene Olevsky
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| Presentation Title |
High Pressure Spark Plasma Sintering Unlocks the Sub-20 nm Frontier in Oxide Nanoceramics |
| Author(s) |
Ricardo Castro |
| On-Site Speaker (Planned) |
Ricardo Castro |
| Abstract Scope |
Spark Plasma Sintering (SPS) is celebrated for rapid densification yet notoriously permits grains to balloon beyond the nanoscale as full density is attained. We show that coupling millisecond current pulses with a modest but well-timed uniaxial pressure ramp that tops out at just 2.2 GPa stabilizes grain growth an order of magnitude lower than conventional SPS records. Fully dense MgAl₂O₄ spinel, 8YSZ, and their biphasic composites are consolidated with average grain sizes below 20 nm and narrow distributions confirmed by SEM and TEM. Access to this unexplored regime reveals an inverse Hall–Petch crossover in hardness and toughness, spotlighting grain-boundary sliding and dislocation starvation as governing mechanisms in oxides. Processing maps derived from time–temperature–pressure–pulse experiments describe the critical window where pressure-driven particle rearrangement outpaces diffusion. The results establish a scalable route to true nanoceramics and open avenues for transparent armor, solid-oxide membranes, and next-generation thermal-barrier coatings. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Ceramics, Powder Materials, Nanotechnology |