About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
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| Presentation Title |
Abnormal Grain Growth as a Microstructural Proxy for Grain Boundary Diffusion in Eu-Doped MgAl2O4 Diffusion Couples |
| Author(s) |
Rashed Mia, Fahima Shaon, Christopher Marvel |
| On-Site Speaker (Planned) |
Rashed Mia |
| Abstract Scope |
Grain boundary diffusion plays a critical role in controlling microstructural evolution in polycrystalline ceramics, yet direct measurement of dopant transport remains challenging, particularly for trace dopants. In this work, polycrystalline diffusion couples consisting of undoped and 500 ppm Eu-doped MgAl2O4 were used to investigate long-range grain boundary transport. Pre-densified compacts were coupled, annealed at 1600°C between 0-16hr, and electron backscattered diffraction was employed to quantify grain size distributions and chart abnormal grain growth (AGG) behavior vs. distance from the original diffusion interface. Eu doping reduced the normal grain growth rate constant by threefold, while abnormal grains grew 100x faster. Furthermore, abnormal grains were observed at distances further from the diffusion interface with increasing annealing time, confirming long-range dopant redistribution along grain boundaries. These results suggest that AGG can serve as a reasonable microstructural proxy for grain boundary diffusion and provide new insight into complexion-mediated transport in oxide ceramics. |