|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Phase Transformations in Multi-component Systems: An MPMD Symposium Honoring Gary R. Purdy
||Grain Boundary Segregation in Phase Separating Nanocrystalline Alloys: The Role of Competing Processes on Microstructure Evolution
||Fadi Abdeljawad, Stephen M. Foiles, Blythe Clark
|On-Site Speaker (Planned)
Recently, grain boundary (GB) segregation in nanocrystalline (NC) alloys has been proposed as a thermodynamic route to mitigate grain growth. In such NC alloys with high nominal solute concentrations, phase separation, an un-mixing process, takes place in addition to grain growth and GB segregation. The interplay between these competing processes sets the morphology and the overall thermal stability of these alloys. Herein, based on a diffuse-interface model capable of incorporating bulk thermodynamics and independently treating solute-GB and solute-solute interactions, we present quantitative analysis of GB segregation in phase separating NC binary alloys and its impact on grain growth dynamics. Simulation results establish a morphology/microstructure map as a function of both heat of segregation and that of phase separation. Additionally, modeling results are qualitatively compared with recent experimental studies on Iron-based and Platinum-based NC binary alloys.
||Planned: A print-only volume