RADIATION-INDUCED GRAIN-BOUNDARY SEGREGATION IN DILUTE ALLOYS

An innovative analytical model of radiation-induced segregation (RIS) in dilute alloys is presented. The approach is based on non-equilibriu m segregation theory and can be extended to cover a multiplicity of si nk types in a wide variety of metallic matrices. The model circumvents the requirement for complex mathematical procedures inherent in curre nt rate theory analyses of RIS. Calculations are made for nickel segre gation to grain boundaries in alpha-Fe and gamma-Fe and for zinc segre gation in silver. Adequate fits between the limited available experime ntal surface segregation data and the model predictions are obtained. The analysis is used to deduce trends in grain boundary segregation in austenitic and ferritic steels to provide insight into materials sele ction for nuclear plants to meet requirements for minimal RIS.