Atomistic investigation of structural changes and reaction energy induced by dislocation-grain boundary interaction process in fcc aluminum and bcc iron

Tsuru, Tomohito   ; Shibutani, Yoji*; Kaji, Yoshiyuki  

Interaction process of grain boundary and dislocation is one of the most important factors in the materials. Dislocations are successively piled up beside the grain boundary planes and they produce stress concentration which becomes a dominant stress factor of stress corrosion cracking (SCC). However, detailed mechanisms of the interaction between these processes and their influence on plastic behavior have yet to be definitively determined. In the present study, fundamental properties of the CSL grain boundaries and grain boundary-dislocations process are investigated by atomistic simulations. Then nudged elastic band (NEB) are performed to evaluate activation energy and minimum energy path in the interaction process of dislocation and CSL. As a result, it is found that there is a strong correlation between grain boundary energy and excess free volume, and that the stable grain boundary can be high energy barrier to grain boundary-dislocation interaction.