Computer simulation of extrinsic grain-boundary defects in the Sigma 11, <101 >{131} symmetric tilt boundary

A computer simulation was performed to investigate the structure and proper ties of extrinsic grain-boundary (GB) defects in the Sigma 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 OK) equilibrium structures. Extrins ic GB dislocations were introduced into the models by application of the ex act anisotropic elastic displacement field for a bicrystal interface. Some dislocations were accompanied by geometrically necessary steps (in which ca se the pair form a disconnection) to avoid formation of GB faults. The stru cture and properties of the equilibrium GB were compared with GBs containin g steps, dislocations and disconnections. A broad range of GB defects was s tudied in order to characterize their potential effect on GB sliding resist ance.