Microstructural evolution of metals and alloys under high temperature irradiation: a contribution

New techniques are proposed for describing yet poorly explored aspects of the microstructural evolution of metals under high temperature irradiation. Dislocation network: it is shown experimentally that the dislocation density is not uniquely defined by the irradiation flux and temperature. The proposed model where the dislocations climb, around fixed pinning points, due to interstitial capture, results in such an hysteresis. Coupling between the dislocation and void evolutions: the state of the microstructure is represented by a point in the appropriate space. The study of the singularities of the velocity field of this point reveals behaviors such as transient or heterogeneous swelling, which find here a simple explanation. Incubation for swelling as a result of solute redistribution: based on the atomistic theory of diffusion, a simple model is proposed for the dependance of the dislocation bias with the matrix solute content. This dependance is introduced in a simple model for swelling. The incubation dose which results exhibits several trends in agreement with published behaviors