Computer simulation of extrinsic grain-boundary defects in the ∑11, 〈101〉{131} symmetric tilt boundary

Abstract

Abstract A computer simulation was performed to investigate the structure and properties of extrinsic grain-boundary (GB) defects in the {11, 〈101〉 {131} symmetric tilt boundary. An embedded-atom method potential was employed to represent aluminium. Standard molecular dynamics relaxation techniques were used to compute low-temperature (about 0 K) equilibrium structures. Extrinsic GB dislocations were introduced into the models by application of the exact anisotropic elastic displacement field for a bicrystal interface. Some dislocations were accompanied by geometrically necessary steps (in which case the pair form a disconnection) to avoid formation of GB faults. The structure and properties of the equilibrium GB were compared with GBs containing steps, dislocations and disconnections. A broad range of GB defects was studied in order to characterize their potential effect on GB sliding resistance.