| About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
|
| Symposium
|
Powder Materials Processing and Fundamental Understanding
|
| Presentation Title |
Interface Energy Control for Improved Mechanical Properties in Oxide Nanoceramics |
| Author(s) |
Ricardo Castro, Isabella L. M. Costa |
| On-Site Speaker (Planned) |
Ricardo Castro |
| Abstract Scope |
Fabrication of dense oxide ceramics requires a refined control over interfacial properties. From the synthesis of the nanopowders to the densification of the final part, the chemistry of interfaces have a definite impact on properties. Here we demonstrate how ionic dopants designed to segregate to the surface of zirconium dioxide nanopowders impact the chemistry of grain boundaries in the final product and can be used to control properties. Gd-doped and undoped zirconia were synthesized by coprecipitation. For an effective sintering, High Pressure Spark Plasma Sintering (HPSPS) was used after degassing of the samples for removal of surface impurities (including water molecules) that could compromise the final produce performance. Dense translucent zirconia pellets were achieved with grain sizes ranging from 20 to hundreds of nanometers. The samples enabled a detailed study of the impact of interfaces on the mechanics of nanoceramics. We demonstrate that Gd-doped cubic zirconia nanopowders show surface segregation which is maintained at the dense counterpart, enabling a unique grain boundary thermochemistry that positively impact mechanical properties. Segregated Gd caused postponement of the Invers Hall-Petch relation to smaller sizes, demonstrating for the first time the phenomenon can be controlled by tuning grain boundaries in oxides. |
| Proceedings Inclusion? |
Planned: |