About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Materials Kinetics and Mechanisms Under External Forcing-Driven Conditions
|
| Presentation Title |
Morphological Transformations of Radiation-Induced Precipitates at Grain Boundaries |
| Author(s) |
Nicholas Saunders, Daniel Vizoso, Remi Dingreville, Robert Averback, Pascal Bellon |
| On-Site Speaker (Planned) |
Nicholas Saunders |
| Abstract Scope |
Precipitates formed at grain boundaries due to radiation-induced segregation (RIS) often undergo morphological transformations that are not determined by equilibrium kinetics. This behavior presents a materials design challenge for irradiation and other nonequilibrium environments. For instance, precipitate films at grain boundaries that would spontaneously break-up by spinodal decomposition at equilibrium can be stabilized under irradiation. To quantify this behavior, we use multiphysics phase-field modeling to predict radiation-induced precipitate morphologies in two-dimensional Ni-Si polycrystals. We construct, using linear stability analyses of constitutive evolution equations, a nonequilibrium phase diagram that predicts grain boundary precipitate morphology as a function of RIS strength, grain size, and alloy composition. Precipitate films are stabilized by strong point defect convection towards grain boundaries in small grains and by higher nominal grain concentrations, but decompose as back-diffusion becomes dominant at larger grain sizes. These predictions are compared to available experimental results for irradiated nanocrystalline Ni-Si thin films. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Phase Transformations, Computational Materials Science & Engineering, Modeling and Simulation |