Abstract: J. Nucl. Mater. (2008) submitted
U. Birkenheuer, F. Bergner, A. Gokhman, A. Ulbricht, F.-P. Weiß
Vacancy-coupled copper precipitation model for irradiated reactor pressure vessel steels
J. Nucl. Mater. (2008) submitted.
A rate theory model for the simulation of the time-evolution of Cu-rich precipitates in Fe-Cu model alloys is presented which takes into account that precipitate clusters are mixed Cu-vacancy aggregates by explicitly allowing the defect clusters to absorb vacancies. The resulting Vacancy-Coupled Copper Clustering (V3C) model is calibrated on a series of SANS experiments on two different Fe-Cu model alloys neutron-irradiated at four different doses. Quantitative agreement with the SANS experiments could be achieved by introducing a dependence of the Fe-Cu interface energy on the amount of vacancies in the mixed precipitate clusters. This energy is a function of the weight-percentage of Cu in the iron matrix. An analytic expression for this dependence is suggested. In addition, the new V3C model is used to gain some preliminary insight into the time-evolution of the chemical composition of the mixed Cu-vacancy clusters, confirming qualitatively the experimental findings.