Irradiation produces in materials excess vacancies and self-interstials that eliminate by mutual recombination or by annihilation at sinks (surfaces, grain boudaries, dislocations).
It sustains permanent fluxes of point defects towards those sinks. In case of preferential transport of one componant of an alloy, the chemical composition is modified in the vicinity of the sinks: a Radiation Induced Segregation (RIS). Its modelling requires a good description of the alloy properties: its driving forces (derived from the thermodynamics) and its kinetic coefficients (the Onsager matrix). The objectif on this project is to combine (i) atomic models (Kinetic Monte Carlo simulations and Self-Consistent Mean Field), fitted on ab initio calculations, that provide the Onsager coeffcients and the driving forces and (ii) a Phase-Field modelling that will give a description of the evolution of the alloy under irradiation at much larger time- and space-scales. The approach will be applied to Fe-Cr and Fe-Cu alloys, already modelled at the atomic scale. RIS will be first modelled near grain boundaries, then near dislocation loops. Special attention will be paid to the effect of elastic stresses on the RIS.