Quantitative Evaluation of Copper Nano Cluster Combination Process by Multi Vacancy Lattice Monte Carlo Simulation

抄録

In this study, we focus on nanoscale copper-rich precipitates and attempt to elucidate their effect on the embrittlement of reactor pressure vessel steels. Our final goal is to evaluate such embrittlement from a microscopic viewpoint on the basis of an atomistic simulation. We develop a multi vacancy lattice Monte Carlo (MVLMC) method that can analyze a model having more than one vacancy. We show that the process of copper clustering consists of two phases-the formation phase and the combination phase. Further, we carry out a detailed analysis of the combination process of a cluster using MVLMC and evaluate the formation mechanism of a cluster using the distance between clusters. We find that when a nanocluster smaller than 1 nm and a cluster of approximately 2 nm coalesce, minute nanoclusters separate from the former cluster and are absorbed by the latter cluster.