[SY-B10] Phase-field modelling of dislocation loop evolution under irradiation : application to radiation induced segregation prediction near the dislocation cores
Understanding and predicting the microstructural evolution of metallic alloys constituting the reactor vessels are crucial issues for safety in the nuclear industry. Under irradiation, point defects (PD) are created and diffuse towards microstructural defects such as dislocations. These microstructural defects will evolve according to their ability to absorb PD, also known as sink strength. Dislocation climb is one consequence of PD absorption and leads to growth or shrinkage of dislocation loops. Phase field (PF) models have already been proposed to describe dislocation climb when only vacancies are considered, which couple non-conservative dislocation motion and vacancy diffusion through an absorption term. To simulate growth/shrinkage of dislocation loops under irradiation in metallic alloys where vacancies but also self-interstitials are created, a new formulation of these models is required, and this will constitute the first part of the presented work. In particular, it will be shown that such a formulation is not a straigthforward generalization of the existing models. Thanks to this new PF model, well-known phenomena observed under irradiation, such as radiation induced segregation, will be studied near the dislocation cores. The particular influence of climb and elastic interactions between PDs and dislocations, generally ignored in RIS calculations, will be discussed in detail.