|About this Abstract
||MS&T23: Materials Science & Technology
||Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
||Examining Multiple Generations of Complexion Transitions in Eu-doped MgAl2O4
||Alicia Koenig, Caroline Riedel, Christopher Marvel, Martin Harmer
|On-Site Speaker (Planned)
This study examines grain boundary complexion nucleation behavior at 1800 °C in Eu-doped MgAl¬2O4 and correlates complexion nucleation to abnormal grain growth kinetics. Computationally modeled time-temperature-transformation (TTT) diagram of abnormal grain growth were previously observed to exhibit C-shaped curves, thereby implying a delay in abnormal grain growth at higher temperatures. This delay was attributed to the notion that sufficiently high complexion nucleation rates diminish the time in which single grains have competitive advantages. To verify this mechanism, annealing treatments were completed using 1≤t≤120 minute dwell times at 1800 °C and several unique complexion transitions, as signified via the onset of abnormal grain growth, were examined using atomic-resolution characterization. Correlations between dwell time, grain boundary complexion type, grain boundary excess measurements, and grain sizes for each grain population type were examined. Importantly, it was confirmed that faster heating rates produced fewer abnormal grains, validating the predictions of the TTT diagram.