Molecular dynamics simulation of Cu atoms interaction with symmetrical grain boundaries of BCC Fe

The interaction between Cu atoms and symmetrical grain boundaries (GB) Σ3{1 1 2} in BCC iron have been simulated with molecular dynamics and Metropolis monte carlo methods. Positive binding energy has been found for substitutional Cu with a symmetrical GB structure, and this positive binding energy increases as the size of the Cu clusters increase. After absorption, the Cu clusters in the GB prefer to be in a state of large size and low density rather than having a high number of randomly distributed smaller sized clusters. The phase transition of Cu-rich precipitates has been observed from BCC to FCC near the GB. These results indicate the possible segregation of Cu atoms to the GB, and provide the information for understanding the precipitation of Cu atoms and its effect on the properties of BCC iron.