About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
|
| Presentation Title |
Heating-Rate Effects on Abnormal Grain Growth in Eu-Doped MgAl2O4 Spinel |
| Author(s) |
Fahima Shaon, Rashed Mia, Alicia Koenig, Thomas Koenig, Martin Harmer, Christopher Marvel |
| On-Site Speaker (Planned) |
Fahima Shaon |
| Abstract Scope |
There has been renewed interest in identifying effects of extreme heating rates on sintering. Recent studies aim to elucidate densification mechanisms associated with equilibrium and non-equilibrium atomic-scale interfaces, specifically related to mapping kinetic pathways that ‘trap’ highly active non-equilibrium grain boundaries. However, heating rate effects on grain-boundary equilibrium during coarsening have been largely ignored. In this study, pre-densified Eu-doped MgAl2O4 samples were annealed up to 1800 °C at heating rates between 10-100 °C/min and characterized using electron backscatter diffraction to chart abrupt changes in grain growth kinetics as a proxy for detecting grain boundary complexion transitions. The results show that slower heating promoted abnormal grain growth more extensively than faster heating rates, likely due to longer incubation times above an equilibrium complexion transformation temperature. The observed behaviors are rationalized by considering complexion kinetic diagrams. In particular, concepts underlying yet to be established complexion continuous heating transformation diagrams will be introduced. |