| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Radiation Effects in Metals and Ceramics
|
| Presentation Title |
H-37: Coupled Bulk and Grain Boundary Compositional Patterning in Binary Immiscible Alloy under Irradiation: A Phase Field Modeling Study |
| Author(s) |
Qun Li, Pascal Bellon, Robert S Averback |
| On-Site Speaker (Planned) |
Qun Li |
| Abstract Scope |
Irradiation of moderately immiscible alloy systems results in competing effects, namely randomization of the composition by ballistic mixing and phase separation driven by thermodynamics. Past modeling and experiments have shown that this competition can lead to bulk compositional patterning, i.e., the stabilization of finite-size intragranular precipitates at steady state. Here we employ phase field modeling to investigate the coupled microstructural evolution of grain interiors and grain boundaries. We find that irradiation can lead to compositional patterning at grain boundaries, and remarkably that it can coexist with bulk patterning. GB precipitates are larger than intragranular ones owing to faster diffusion along GBs. We analyze these results by building steady-state maps as a function of the nominal composition and the forcing intensity γb, the ratio of ballistic mixing rate to thermal mobility. The double grain interior-GB patterning suggests that suitable coupling of these sub-systems can result in self-organization of the whole microstructure. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |