Convection-induced compositional patterning at grain boundaries in irradiated alloys

We consider the stability of precipitates formed at grain boundaries (GBs) by radiation-induced segregation in dilute alloys subjected to irradiation. The effects of grain size and misorientation of symmetric-tilt GBs are quantified using phase field modeling. A novel regime is identified where, at long times, GBs are decorated by precipitate patterns that resist coarsening. Maps of the diffusional P\'eclet number indicate that arrested coarsening takes place when solute advection dominates over thermal diffusion right up to the precipitate/matrix interface, overwhelming capillary effects. This contrasts with liquid-solid mixtures where convection only accelerates coarsening.Comment: 29 pages, main text with 3 figures, 1 table, 1 supplemental information documen

3D phase-field modelling of dislocation loop sink strengths

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Phase-field modeling of precipitate evolution dynamics in elastically inhomogeneous low-symmetry systems: Application to hydride precipitation in Zr

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Influence of shape anisotropy of self-interstitials on dislocation sink efficiencies in Zr: Multiscale modeling

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Quantitative phase field model for dislocation sink strength calculations

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A new scenario for ‹c› vacancy loop formation in zirconium based on atomic-scale modeling

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First-principles study of Al-Cu energetics and consequences on athermal formation of Cu-rich compounds

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Multiscale Modeling of Radiation Induced Segregation in Iron Based Alloys

International audienceIn metallic alloys of fission or fusion reactors, microstructural evolution results from a dynamic equilibrium between thermodynamic forces and the production of defects by irradiation. The migration of defects can lead to the formation of clusters of defects (nano-cavities, dislocation loops, nano-precipitates) or variations in chemical composition close to the defect sinks, a phenomenon known as Radiation Induced Segregation (RIS). To predict the effect of irradiation conditions (type of irradiation particle, dose rate, temperature), phenomenological diffusion models exist that have to be assembled to give an overall description. Our objective is to describe these models and to propose numerical implementations to solve them starting at the atomic scale (DFT energy calculations, Kinetic Monte Carlo, Self-Consistent Mean Field approaches) to reach the mesoscopic one using the phase field modeling. This multi-scale approach is illustrated by a short review of recent studies focusing on dilute and concentrated iron based alloys

Mechanisms of formation of Al4Cu9 during mechanical alloying: An experimental study

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