About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
|
Defects and Interfaces: Modeling and Experiments
|
Presentation Title |
Grain Boundary Doping in Magnesium Aluminate Spinel Nanoceramics for Improved Toughness |
Author(s) |
Isabella L.M. Costa, Ghanshyam Pilania, Blas P. Uberuaga, Ricardo Castro |
On-Site Speaker (Planned) |
Ricardo Castro |
Abstract Scope |
Interface engineering at the atomic level may influence bulk materials’ thermochemical properties, particularly when dealing with grain sizes in the nanoscale dimension. Here we designed a dopant to segregate to grain boundaries of Magnesium Aluminate spinel. Using a combination of DFT and atomistic simulation, we determined that Sodium would segregate to the grain boundaries of MgAl2O4, reducing local excess energies. Atomistic simulations on the mechanical strength of selected grain boundaries showed that doping enhanced the local strength and toughness, with Sodium playing a key role in accommodating defects during fracturing. MgAl2O4 was then synthesized and doped with Sodium. Densification using High Pressure Spark Plasma Sintering enabled the formation of dense transparent spinel parts with grain sizes below 20nm. While hardness of the doped system was measured to be below the undoped system, the Sodium containing spinel presented increased toughness, consistent with atomistic simulation predictions. |
Proceedings Inclusion? |
Planned: |