Rate theory and SANS study of phase separation in a neutron irradiated Fe-12.5at%Cr model alloy

Cluster dynamics (CD) is used to study the evolution of the size distributions of vacancy clusters (VC), self-interstitial atom (SIA) clusters (SIAC) and Cr-precipitates in neutron irradiated Fe-12.5at%Cr alloy at the irradiation doses up to 12 dpa, fluence about 140 ndpa/s and T=300 C. Transmission electron microscopy (TEM) and small angle neutron scattering (SANS) data [1,2] on the defect structure of this material irradiated at the doses of 0.6 and 1.5 dpa are used to calibrate the model. It was found the saturation behaviour of free vacancy and free SIA concentrations, number density of SIAC and Cr-precipitates volume fraction for neutron expose great than 0.006 dpa; strong peak of SIAC with the average diameter about 0.5 nm and presence of VC with radius less 0.5 nm.